（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

1. error: expected unqualified-id before ‘for’