Question

How to generate all possible permutations of int array using next_permutation in C++

Answer 1

#include <iostream>
#include <algorithm> 

void print_array(int arr[], int size) { 
    for (int i = 0; i < size; i++) { 
        std::cout << arr[i] << "  "; 
    } 
    std::cout << "\n"; 
} 
  
void findPermutations(int arr[], int size) { 
    std::sort(arr, arr + size); 

    do { 
        print_array(arr, size); 
    } while (std::next_permutation(arr, arr + size)); 
} 
  
int main(void) 
{ 
    int arr[] = { 1, 2, 3, 4 }; 

    findPermutations(arr, sizeof(arr) / sizeof(arr[0])); 
  
    return 0; 
} 
 
 
 
 
/*
run:
 
1  2  3  4  
1  2  4  3  
1  3  2  4  
1  3  4  2  
1  4  2  3  
1  4  3  2  
2  1  3  4  
2  1  4  3  
2  3  1  4  
2  3  4  1  
2  4  1  3  
2  4  3  1  
3  1  2  4  
3  1  4  2  
3  2  1  4  
3  2  4  1  
3  4  1  2  
3  4  2  1  
4  1  2  3  
4  1  3  2  
4  2  1  3  
4  2  3  1  
4  3  1  2  
4  3  2  1  

*/
  

 

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