【洛谷】P1216 数字三角形

import java.io.IOException;
import java.util.Scanner;public class P1216_数字三角形_DP_原版 {public static void main(String[] args) {Scanner sc = new Scanner(System.in);int n = sc.nextInt();int[][] dp = new int[n + 1][n + 1];int t;for (int i = 1; i <= n; i++) {for (int j = 1; j <= i; j++) {t = sc.nextInt();dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - 1]) + t;}}int res = 0;for (int i = 1; i <= n; i++) {res = Math.max(res,dp[n][i]);}System.out.println(res);}
}

先用DP，结果由于Java本身的内存占用大，不能AC：

现在进行输入优化：

来自：数字三角形 Number Triangles（java的MLE解决办法） - 吐司奶猫荷包蛋 - 博客园 (cnblogs.com)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;public class P1216_数字三角形_DP {public static void main(String[] args) throws IOException {InputReader in = new InputReader(System.in);int n = in.nextInt();int[][] dp = new int[n + 1][n + 1];int t;for (int i = 1; i <= n; i++) {for (int j = 1; j <= i; j++) {t = in.nextInt();dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - 1]) + t;}}int res = 0;for (int i = 1; i <= n; i++) {res = Math.max(res, dp[n][i]);}System.out.println(res);}static class InputReader {BufferedReader br;public InputReader(InputStream stream) {br = new BufferedReader(new InputStreamReader(stream));}public int nextInt() throws IOException {int c = br.read(); // 从输入流中读取一个字符的 ASCII 码，并将其存储在变量c中while (c <= 32) { //跳过输入流中的空白字符c = br.read();}boolean negative = false; // 负号if (c == '-') {negative = true;c = br.read();}int x = 0;while (c > 32) {x = x * 10 + c - '0';c = br.read();}return negative ? -x : x;}public long nextLong() throws IOException {int c = br.read();while (c <= 32) {c = br.read();}boolean negative = false;if (c == '-') {negative = true;c = br.read();}long x = 0;while (c > 32) {x = x * 10 + c - '0';c = br.read();}return negative ? -x : x;}public String next() throws IOException {int c = br.read();while (c <= 32) {c = br.read();}StringBuilder sb = new StringBuilder();while (c > 32) {sb.append((char) c);c = br.read();}return sb.toString();}public double nextDouble() throws IOException {return Double.parseDouble(next());}}
}