双层循环跑了几次
同一个数组,改成两层嵌套。运行下面这段程序:
#include <iostream>
#include <string>
#include <vector>
using namespace std;
int main() {
vector<int> A = {17, 24, 15, 13, 23};
int ops = 0;
for (int x : A) {
for (int y : A) {
(void)x; (void)y;
ops++;
}
}
cout << ops << endl;
}
(本题用 g++ -std=c++17 -O0 编译。)