目录
046:字符串替换
047:神奇数
048:DNA序列
046:字符串替换
字符串替换_牛客题霸_牛客网 (nowcoder.com)
题目：
题解：
简单模拟题~
class StringFormat {
public:string formatString(string str, int n, vector<char> arg, int m) {string ret;int j=0;for(int i=0;i<str.size();i++){if((str[i]<='Z' && str[i]>='A') || (str[i]<='z' && str[i]>='a')){ret+=str[i];}else{ret+=arg[j++];i++;}}while(j<arg.size()){ret+=arg[j++];}return ret;}
};047:神奇数
神奇数_牛客笔试题_牛客网 (nowcoder.com)
题解：
根据题意模拟就行，注意不要有前导0的情况。
#include <iostream>
#include<string>
#include<cmath>
using namespace std;bool isPrime(int num) {if (num < 2) return false;for (int i = 2; i <= sqrt(num); ++i) {if (num % i == 0) {return false;}}return true;
}bool check(int k) {string str = to_string(k);int n = str.size();for (int i = 0; i < n - 1; i++) {for (int j = i + 1; j < n; j++) {if (str[i] == '0' && str[j] == '0') {continue;}if (str[i] == '0') {int num2 = (str[j] - '0') * 10 + (str[i] - '0');if (isPrime(num2)) {return true;}}if (str[j] == '0') {int num1 = (str[i] - '0') * 10 + (str[j] - '0');if (isPrime(num1)) {return true;}}if (str[i] != '0' && str[j] != '0') {int num1 = (str[i] - '0') * 10 + (str[j] - '0');int num2 = (str[j] - '0') * 10 + (str[i] - '0');if (isPrime(num1) || isPrime(num2)) {return true;}}//}}}return false;
}int main() {int a, b = 0;cin >> a >> b;int ret = 0;for (int k = a; k <= b; k++) {if (check(k)) {//cout<<k<<endl;ret++;}}cout << ret << endl;return 0;}048:DNA序列
DNA序列_牛客题霸_牛客网 (nowcoder.com)
题目：
题解：
固定长度的滑动窗口：
1.进窗口
2.判断
3.出窗口
4.更新结果
#include <iostream>
#include <string>
using namespace std;
string s;
int x;
int main() {cin >> s >> x;int begin = -1; // 标记结果的起始位置int maxCount = 0; // 存储之前的窗⼝⾥⾯ C + G 的个数int count = 0; // 统计窗⼝内 C + Gint left = 0, right = 0, n = s.size();while (right < n) {if (s[right] == 'C' || s[right] == 'G') count++;while (right - left + 1 > x) {if (s[left] == 'C' || s[left] == 'G') count--;left++;//出窗口}//更新结果if (right - left + 1 == x) {if (count > maxCount) {begin = left;maxCount = count;}}right++;//进窗口}cout << s.substr(begin, x) << endl;return 0;
}
)
