【蓝桥杯练习系统】基础练习（Java）（普通试题数+VIP试题数）

“蓝桥杯”练习系统 (lanqiao.cn)

基础入门

BASIC-01 A+B问题入门

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int A = scanner.nextInt();int B = scanner.nextInt();System.out.println(A + B);}
}

BASIC-02 序列求和入门求和公式

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner in = new Scanner(System.in);long n = in.nextLong();System.out.println(n * (n + 1) / 2);}
}

BASIC-03 圆的面积入门实数输出

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int r = scanner.nextInt();double area = Math.PI * r * r;System.out.printf("%.7f%n", area);}
}

BASIC-04 Fibonacci数列入门数列取模

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int n = scanner.nextInt(), a = 1, b = 1, sum;for (int i = 3; i <= n; i++) {sum = (a + b) % 10007;a = b;b = sum;}System.out.println(b);}
}

基础练习

BASIC-1 闰年判断条件判断

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner in = new Scanner(System.in);int n = in.nextInt();System.out.println((n % 4 == 0 && n % 100 != 0) || (n % 400 == 0) ? "yes" : "no");}
}

BASIC-2 01字串循环

public class Main {public static void main(String[] args) {for (int i = 0; i < 32; i++) {String binaryString = Integer.toBinaryString(i);binaryString = String.format("%5s", binaryString).replace(' ', '0');System.out.println(binaryString);}}
}

BASIC-3 字母图形循环字符串

import java.io.*;
import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner in = new Scanner(System.in);PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));int n = in.nextInt(), m = in.nextInt();for (int i = 0; i < n; i++) {StringBuilder sb = new StringBuilder();for (int j = 0; j < m; j++) {sb.append((char) ('A' + Math.abs(j - i)));}out.println(sb);}out.flush();}
}

BASIC-4 数列特征循环最大值最小值累加

import java.io.*;public class Main {static QuickInput in = new QuickInput();static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));public static void main(String[] args) throws IOException {int n = in.nextInt(), min = 10000, max = -10000, sum = 0;for (int i = 0; i < n; i++) {int x = in.nextInt();min = Math.min(min, x);max = Math.max(max, x);sum += x;}out.println(max);out.println(min);out.println(sum);out.flush();}static class QuickInput {StreamTokenizer input = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));public int nextInt() throws IOException {input.nextToken();return (int) input.nval;}}
}

BASIC-5 查找整数循环判断

import java.io.*;
import java.util.*;public class Main {static QuickInput in = new QuickInput();public static void main(String[] args) throws IOException {int n = in.nextInt();Map<Integer, Integer> map = new HashMap<>();for (int i = 1; i <= n; i++) {map.putIfAbsent(in.nextInt(), i);}System.out.println(map.getOrDefault(in.nextInt(), -1));}static class QuickInput {StreamTokenizer input = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));public int nextInt() throws IOException {input.nextToken();return (int) input.nval;}}
}

BASIC-6 杨辉三角形基础练习二维数组

import java.io.*;
import java.util.Scanner;public class Main {static int[][] arr;public static void main(String[] args) {Scanner in = new Scanner(System.in);PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));int n = in.nextInt();arr = new int[n][n];for (int i = 0; i < n; i++) {for (int j = 0; j <= i; j++) {arr[i][j] = f(i, j);out.print(f(i, j) + " ");}out.println();}out.println();out.flush();}static int f(int i, int j) {if (arr[i][j] != 0) return arr[i][j];if (j == 0 || i == j) return 1;return f(i - 1, j - 1) + f(i - 1, j);}
}

BASIC-7 特殊的数字循环判断数位

public class Main {public static void main(String[] args) {for (int i = 100; i < 1000; i++) {if (i == (Math.pow(i / 100, 3) + Math.pow((i / 10) % 10, 3) + Math.pow(i % 10, 3))) {System.out.println(i);}}}
}

BASIC-8 回文数循环判断回文数

import java.io.*;public class Main {public static void main(String[] args) {PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));for (int i = 1000; i < 10000; i++) {String s = String.valueOf(i);if (s.equals(new StringBuilder(s).reverse().toString())) out.println(s);}out.flush();}
}

BASIC-9 特殊回文数回文数循环条件语句

import java.io.*;
import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner in = new Scanner(System.in);PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));int n = in.nextInt();for (int i = 10000; i < 1000000; i++) {String s = String.valueOf(i);StringBuilder sb = new StringBuilder(s);int num = 0;for (int j : sb.chars().toArray()) num += j - '0';if (num == n && s.equals(sb.reverse().toString())) out.println(s);}out.flush();}
}

BASIC-10 十进制转十六进制循环整除求余判断

import java.io.*;public class Main {public static void main(String[] args) throws IOException {BufferedReader in = new BufferedReader(new InputStreamReader(System.in));PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));int res = Integer.parseInt(in.readLine());StringBuilder sb = new StringBuilder();if (res == 0) sb.append(0);while (res > 0) {int temp = res % 16;char c = (char) ('0' + temp);if (temp > 9) c = (char) ('A' + (temp - 10));sb = new StringBuilder(String.valueOf(c) + sb);res /= 16;}out.println(sb);out.flush();}
}

BASIC-11 十六进制转十进制进制转换字符处理判断

import java.io.*;public class Main {public static void main(String[] args) throws IOException {BufferedReader in = new BufferedReader(new InputStreamReader(System.in));PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));String s = in.readLine();long res = 0;for (int i = 0; i < s.length(); i++) {int t;if (s.charAt(i) >= '0' && s.charAt(i) <= '9') {t = s.charAt(i) - '0';} else {t = s.charAt(i) - 'A' + 10;}res += t * Math.pow(16, s.length() - i - 1);}out.println(res);out.flush();}
}

BASIC-12 十六进制转八进制进制转换字符循环

import java.io.*;public class Main {public static void main(String[] args) throws IOException {BufferedReader in = new BufferedReader(new InputStreamReader(System.in));PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));int n = Integer.parseInt(in.readLine());for (int i = 0; i < n; i++) {String s = in.readLine();StringBuilder temp = new StringBuilder();for (int j = 0; j < s.length(); j++) {switch (s.charAt(j)) {case '0':temp.append("0000");break;case '1':temp.append("0001");break;case '2':temp.append("0010");break;case '3':temp.append("0011");break;case '4':temp.append("0100");break;case '5':temp.append("0101");break;case '6':temp.append("0110");break;case '7':temp.append("0111");break;case '8':temp.append("1000");break;case '9':temp.append("1001");break;case 'A':temp.append("1010");break;case 'B':temp.append("1011");break;case 'C':temp.append("1100");break;case 'D':temp.append("1101");break;case 'E':temp.append("1110");break;case 'F':temp.append("1111");break;default:break;}}int mod = temp.length() % 3;if (mod == 1) temp = new StringBuilder("00" + temp);if (mod == 2) temp = new StringBuilder("0" + temp);for (int j = 0; j < temp.length(); j += 3) {int res = (temp.charAt(j) - '0') * 4 + (temp.charAt(j + 1) - '0') * 2 + (temp.charAt(j + 2) - '0');if (j == 0 && res == 0) continue;out.print(res);}out.println();}out.flush();}
}

BASIC-13 数列排序数组排序

import java.io.*;
import java.util.Arrays;public class Main {static QuickInput in = new QuickInput();public static void main(String[] args) throws IOException {int n = in.nextInt();int[] a = new int[n];for (int i = 0; i < n; i++) {a[i] = in.nextInt();}Arrays.sort(a);System.out.println(Arrays.toString(a).replaceAll("[\\[\\],]", ""));}static class QuickInput{StreamTokenizer input = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));int nextInt() throws IOException {input.nextToken();return (int) input.nval;}}
}

VIP试题

BASIC-14 时间转换取余数字字符混合输出

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int t = scanner.nextInt(); // 读取输入的时间（秒）int hours = t / 3600; // 计算小时int remainingSeconds = t % 3600; // 计算剩余的秒数int minutes = remainingSeconds / 60; // 计算分钟int seconds = remainingSeconds % 60; // 计算最终的秒数System.out.println(hours + ":" + minutes + ":" + seconds);}
}

BASIC-15 字符串对比字符串大小写

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);String str1 = scanner.nextLine().trim();String str2 = scanner.nextLine().trim();// 比较字符串长度if (str1.length() != str2.length()) {System.out.println(1);} else if (str1.equals(str2)) {// 完全一致（区分大小写）System.out.println(2);} else if (str1.equalsIgnoreCase(str2)) {// 不区分大小写的情况下完全一致System.out.println(3);} else {// 即使不区分大小写也不能使这两个字符串一致System.out.println(4);}}
}

BASIC-16 分解质因数质数分解循环

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;public class Main {public static List<Integer> sieveOfEratosthenes(int n) {List<Integer> primes = new ArrayList<>();boolean[] isPrime = new boolean[n + 1];for (int i = 2; i <= n; i++) isPrime[i] = true;for (int i = 2; i * i <= n; i++) {if (isPrime[i]) {primes.add(i);for (int j = i * i; j <= n; j += i) {isPrime[j] = false;}}}return primes;}public static List<Integer> primeFactorization(int n, List<Integer> primes) {List<Integer> factors = new ArrayList<>();for (int prime : primes) {while (n % prime == 0) {factors.add(prime);n /= prime;}}if (n != 1) factors.add(n);return factors;}public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int a = scanner.nextInt();int b = scanner.nextInt();List<Integer> primes = sieveOfEratosthenes(b);for (int i = a; i <= b; i++) {List<Integer> factors = primeFactorization(i, primes);System.out.print(i + "=");if (factors.isEmpty()) {System.out.print(i);} else {System.out.print(factors.get(0));}for (int j = 1; j < factors.size(); j++) {System.out.print("*" + factors.get(j));}System.out.println();}}
}

BASIC-17 矩阵乘法二维数组循环矩阵

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int N = scanner.nextInt();int M = scanner.nextInt();int[][] A = new int[N][N];// 读取矩阵Afor (int i = 0; i < N; i++) {for (int j = 0; j < N; j++) {A[i][j] = scanner.nextInt();}}// 计算A的M次幂int[][] result = matrixPower(A, M);// 输出结果for (int i = 0; i < N; i++) {for (int j = 0; j < N; j++) {System.out.print(result[i][j] + " ");}System.out.println();}}public static int[][] matrixMultiply(int[][] A, int[][] B) {int n = A.length;int[][] C = new int[n][n];for (int i = 0; i < n; i++) {for (int j = 0; j < n; j++) {for (int k = 0; k < n; k++) {C[i][j] += A[i][k] * B[k][j];}}}return C;}public static int[][] matrixPower(int[][] A, int M) {if (M == 0) {int n = A.length;int[][] identity = new int[n][n];for (int i = 0; i < n; i++) {identity[i][i] = 1;}return identity; // 返回单位矩阵}if (M % 2 == 1) {return matrixMultiply(A, matrixPower(A, M - 1));}int[][] halfPower = matrixPower(A, M / 2);return matrixMultiply(halfPower, halfPower);}
}

BASIC-18 矩形面积交判断线段交

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);// 读取第一个矩形的坐标double[] a1 = new double[4];for (int i = 0; i < 4; i++) a1[i] = scanner.nextDouble();// 读取第二个矩形的坐标double[] a2 = new double[4];for (int i = 0; i < 4; i++) a2[i] = scanner.nextDouble();// 计算相交矩形的左下和右上顶点坐标double[] a3 = new double[4];a3[0] = Math.max(Math.min(a1[0], a1[2]), Math.min(a2[0], a2[2]));a3[1] = Math.max(Math.min(a1[1], a1[3]), Math.min(a2[1], a2[3]));a3[2] = Math.min(Math.max(a1[0], a1[2]), Math.max(a2[0], a2[2]));a3[3] = Math.min(Math.max(a1[1], a1[3]), Math.max(a2[1], a2[3]));// 判断是否相交if (a3[0] > a3[2] || a3[1] > a3[3]) {System.out.print("0.00");} else {// 计算交集面积double area = Math.abs(a3[2] - a3[0]) * Math.abs(a3[3] - a3[1]);System.out.printf("%.2f", area);}}
}

BASIC-19 完美的代价贪心算法

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int n = scanner.nextInt();scanner.nextLine();char[] s = scanner.nextLine().toCharArray();int swaps = findMinSwapsToPalindrome(s, n);if (swaps == -1) {System.out.println("Impossible");} else {System.out.println(swaps);}}private static int findMinSwapsToPalindrome(char[] s, int n) {int r = n - 1, cnt = 0, idx = 0;for (int i = 0; i < r; i++) {for (int j = r; j >= i; j--) {if (i == j){if (n % 2 == 0 || idx == 1) {return -1;}idx = 1;cnt += n / 2 - i;}else if (s[i] == s[j]){for (int l = j; l < r; l++) {char t = s[l];s[l] = s[l + 1];s[l + 1] = t;cnt++;}r--;break;}}}return cnt;}
}

BASIC-20 数的读法判断函数

import java.util.Scanner;public class Main {private static final String[] UNITS = {"ling", "yi", "er", "san", "si", "wu", "liu", "qi", "ba", "jiu"};private static final String[] PLACE_VALUES = {"", "shi", "bai", "qian", "wan", "shi", "bai", "qian", "yi", "shi"};public static String numberToChinese(String num) {int n = num.length();StringBuilder sb = new StringBuilder();for (int i = 0; i < n; i++) {int digit = num.charAt(i) - '0';if (digit == 0) {if (n - i == 5 || n - i == 9) sb.append(" ");if (n - i != 1 && num.charAt(i + 1) != '0') sb.append("ling ");} else if ((n == 2 || n == 6 || n == 10) && digit == 1 && i == 0) {sb.append("shi ");} else {sb.append(UNITS[digit] + " " + PLACE_VALUES[n - i - 1] + " ");}}return sb.toString();}public static void main(String[] args) {Scanner scanner = new Scanner(System.in);String num = scanner.next();scanner.close();String chinese = numberToChinese(num);System.out.println(chinese);}
}

BASIC-21 Sine之舞字符串递归递推

import java.util.Scanner;public class Main {private static String An(int n, int i) {if (i == n) return "sin(" + n + ")";if (i % 2 == 0) return "sin(" + i + "+" + An(n, i + 1) + ")";return "sin(" + i + "-" + An(n, i + 1) + ")";}private static String Sn(int n, int i) {if (n == 1) return An(n, 1) + "+" + i;return "(" + Sn(n - 1, i + 1) + ")" + An(n, 1) + "+" + i;}public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int n = scanner.nextInt();System.out.println(Sn(n, 1));}
}

BASIC-22 FJ的字符串字符串递归

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int N = scanner.nextInt();System.out.println(generateSequence(N));}public static String generateSequence(int N) {if (N == 1) {return "A";} else {char c = (char) (N - 1 + 'A');return generateSequence(N - 1) + c + generateSequence(N - 1);}}
}

BASIC-23 芯片测试算法基础统计二维数组

import java.io.*;public class Main {public static void main(String[] args) throws IOException {QuickInput in = new QuickInput();PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));int n = in.nextInt();int[][] arr = new int[n][n];for (int i = 0; i < n; i++) {for (int j = 0; j < n; j++) {arr[i][j] = in.nextInt();}}for (int i = 0; i < n; i++) {int ans = 0;for (int j = 0; j < n; j++) {if (arr[j][i] == 1) ans++;}if (ans > n / 2) out.print((i + 1) + " ");}out.flush();}static class QuickInput {StreamTokenizer input = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));int nextInt() throws IOException {input.nextToken();return (int) input.nval;}}
}

BASIC-24 龟兔赛跑预测数组模拟

import java.util.Scanner;public class Main {public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int v1 = scanner.nextInt(); // 兔子的速度int v2 = scanner.nextInt(); // 乌龟的速度int t = scanner.nextInt();  // 兔子领先t米时停止的时间int s = scanner.nextInt();  // 兔子休息的时间int l = scanner.nextInt();  // 赛道的长度int rabbitPosition = 0;int turtlePosition = 0;int time = 0;while(rabbitPosition < l && turtlePosition < l) {rabbitPosition += v1;turtlePosition += v2;time++;if (rabbitPosition == l || turtlePosition == l) {break;}if (rabbitPosition - turtlePosition >= t) {rabbitPosition -= v1 * s;}}if (rabbitPosition > turtlePosition) {System.out.println("R");} else if(turtlePosition > rabbitPosition) {System.out.println("T");} else {System.out.println("D");}System.out.println(time);}
}

BASIC-25 回形取数二维数组循环

import java.io.*;public class Main {static QuickInput in = new QuickInput();static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));public static void main(String[] args) throws IOException {int m = in.nextInt();int n = in.nextInt();int[][] matrix = new int[m][n];for (int i = 0; i < m; i++) {for (int j = 0; j < n; j++) {matrix[i][j] = in.nextInt();}}int i = 1, j = 0, cnt = 1;System.out.print(matrix[0][0]);matrix[0][0] = -1;while(m * n > cnt) {while (i < m && matrix[i][j] != -1) {out.print(" " + matrix[i][j]);matrix[i][j] = -1;i++;cnt++;}i--;j++;while (j < n && matrix[i][j] != -1) {out.print(" " + matrix[i][j]);matrix[i][j] = -1;j++;cnt++;}i--;j--;while (i >= 0 && matrix[i][j] != -1) {out.print(" " + matrix[i][j]);matrix[i][j] = -1;i--;cnt++;}i++;j--;while (j >= 0 && matrix[i][j] != -1) {out.print(" " + matrix[i][j]);matrix[i][j] = -1;j--;cnt++;}j++;i++;}out.flush();}static class QuickInput {StreamTokenizer input = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));public int nextInt() throws IOException {input.nextToken();return (int) input.nval;}}
}

BASIC-26 报时助手字符串条件判断

import java.util.Scanner;public class Main {private static final String[] UNITS = {"zero", "one", "two", "three", "four", "five","six", "seven", "eight", "nine", "ten", "eleven", "twelve","thirteen", "fourteen", "fifteen", "sixteen", "seventeen","eighteen", "nineteen"};private static final String[] PLACE_VALUES = {"twenty", "thirty", "forty", "fifty"};private static void f(int n) {if (n < 20) {System.out.print(UNITS[n] + " ");} else {System.out.print(PLACE_VALUES[n / 10 - 2] + " ");int t = n % 10;if (t > 0) System.out.print(UNITS[t] + " ");}}public static void main(String[] args) {Scanner scanner = new Scanner(System.in);int h = scanner.nextInt();int m = scanner.nextInt();f(h);if (m == 0) System.out.println("o'clock");else f(m);}
}

BASIC-27 2n皇后问题八皇后问题搜索

import java.util.Scanner;public class Main {static int[][] a = new int[10][10];static int[][] bj = new int[3][20];static int[][] bj1 = new int[3][20];static int n;static long sum = 0;public static void main(String[] args) {Scanner scanner = new Scanner(System.in);n = scanner.nextInt();for (int i = 0; i < n; i++) {for (int j = 0; j < n; j++) {a[i][j] = scanner.nextInt();}}f(0);System.out.println(sum);scanner.close();}public static void f2(int x) {for (int y = 0; y < n; y++) {if (a[x][y] == 1 && bj1[0][y] == 0 && bj1[1][x + y] == 0 && bj1[2][x - y + n] == 0) {a[x][y] = 3;bj1[0][y] = bj1[1][x + y] = bj1[2][x - y + n] = 1;if (x == n - 1) {sum++;} else {f2(x + 1);}bj1[0][y] = bj1[1][x + y] = bj1[2][x - y + n] = 0;a[x][y] = 1;}}}public static void f(int x) {for (int y = 0; y < n; y++) {if (a[x][y] == 1 && bj[0][y] == 0 && bj[1][x + y] == 0 && bj[2][x - y + n] == 0) {a[x][y] = 2;bj[0][y] = bj[1][x + y] = bj[2][x - y + n] = 1;if (x == n - 1) {f2(0);} else {f(x + 1);}bj[0][y] = bj[1][x + y] = bj[2][x - y + n] = 0;a[x][y] = 1;}}}
}

BASIC-28 Huffuman树贪心 Huffuman

import java.io.*;
import java.util.PriorityQueue;public class Main {static QuickInput in = new QuickInput();static PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));public static void main(String[] args) throws IOException {int n = in.nextInt();PriorityQueue<Integer> queue = new PriorityQueue<>();for (int i = 0; i < n; i++) {queue.add(in.nextInt());}long ans = 0;while (!queue.isEmpty()) {int a = queue.poll();if (queue.isEmpty()) break;a += queue.poll();ans += a;queue.add(a);}out.println(ans);out.flush();}static class QuickInput {StreamTokenizer input = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));public int nextInt() throws IOException {input.nextToken();return (int) input.nval;}}
}

BASIC-29 高精度加法数组高精度

import java.io.*;
import java.math.BigInteger;public class Main {public static void main(String[] args) throws IOException {BufferedReader in = new BufferedReader(new InputStreamReader(System.in));PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));BigInteger a = new BigInteger(String.valueOf(in.readLine()));BigInteger b = new BigInteger(String.valueOf(in.readLine()));out.println(a.add(b));out.flush();}
}

BASIC-30 阶乘计算高精度

import java.io.*;
import java.math.BigInteger;public class Main {public static void main(String[] args) throws IOException {BufferedReader in = new BufferedReader(new InputStreamReader(System.in));PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));int n = Integer.parseInt(in.readLine());BigInteger ans = new BigInteger(String.valueOf(1));for (int i = 2; i <= n; i++) {BigInteger t = new BigInteger(String.valueOf(i));ans = ans.multiply(t);}out.println(ans);out.flush();}
}