Question

How to initialize two dimensional (2D) vector with specific same value in C++

Answer 1

#include <iostream>
#include <vector>
 
#define ROWS 3
#define COLS 4
 
int main()
{
    int N = 3;

    std::vector<std::vector<int>> v(ROWS, std::vector<int>(COLS, N));
 
    for (int i = 0; i < v.size(); i++) {
        for (int j = 0; j < v[0].size(); j++) {
            std::cout << v[i][j] << " ";
        }
        std::cout << "\n";
    }
 
    return 0;
}
   
   
   
   
/*
run:
 
3 3 3 3 
3 3 3 3 
3 3 3 3 
    
*/

 

70+ SQL courses for beginners and professionals

Answer 2

#include <iostream>
#include <vector>
  
#define ROWS 3
#define COLS 4
  
int main()
{
    int N = 3;
 
    std::vector<int> vcols(COLS, N);
    std::vector<std::vector<int>> v(ROWS, vcols);
  
    for (int i = 0; i < v.size(); i++) {
        for (int j = 0; j < v[0].size(); j++) {
            std::cout << v[i][j] << " ";
        }
        std::cout << "\n";
    }
  
    return 0;
}
    
    
    
    
/*
run:
  
3 3 3 3 
3 3 3 3 
3 3 3 3 
     
*/

 

70+ SQL courses for beginners and professionals