5 2 0 (a)
7 4 0 (b)
4 8 7 (c)
4 8 7 (c)
5 2 0 (a)
7 4 0 (b)
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
bool cmp(vector<int> v1, vector<int> v2){
return v1[0] < v2[0];
}
int main(){
ios::sync_with_stdio(0), cin.tie(0);
vector<vector<int>> v{{5, 2, 0},
{7, 4, 0},
{4, 8, 7}};
int m = v.size(); //rows
int n = v[0].size(); //columns
cout << "Before:\n";
for(int i=0; i<m; i++){
for(int j=0; j<n; j++)
cout << v[i][j] << ' ';
cout << '\n';
}
sort(v.begin(), v.end(), cmp);
cout << "\nAfter:\n";
for(int i=0; i<m; i++){
for(int j=0; j<n; j++)
cout << v[i][j] << ' ';
cout << '\n';
}
}