（20200714已解决）error: expected unqualified-id before ‘for’

问题描述

如题所示

#include <iostream>
using namespace std;
vector<vector<int>> matrix(n, std::vector<int>(n));
for ( size_t i = 0; i < n; ++i )
{
   matrix[i][i] = 1;
}

解决方案

for循环在函数体外

#include <iostream>
using namespace std;
vector<vector<int>> matrix(n, std::vector<int>(n));
int main(){
    for ( size_t i = 0; i < n; ++i )
    {
       matrix[i][i] = 1;
    }
}

References