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  1. #include <stdio.h>
  2. int bit_test(unsigned long *flg, int pos){
  3.     return((*flg) >> pos & 1UL);
  4. }
  5. void bit_set(unsigned long *flg, int pos){
  6.     *flg |= 1UL << pos;
  7. }
  8. void bit_reset(unsigned long *flg, int pos){
  9.     *flg &= ~(1UL << pos);
  10. }
  11. void f(int arr[], unsigned long *flg, int n, int m){
  12.     int i;
  13.     if(m == 0){
  14.         for(i = 0; i < n; i++){
  15.             printf("%d ", arr[i]+1);
  16.         }
  17.         printf("\n");
  18.         return;
  19.     }
  20.     for(i = 0; i < n; i++){
  21.         if(!bit_test(flg, i)){
  22.             bit_set(flg, i);
  23.             arr[n-m] = i;
  24.             f(arr, flg, n, m-1);
  25.             bit_reset(flg, i);
  26.         }
  27.     }
  28. }
  29. int main(void){
  30.     int arr[64], n;
  31.     unsigned long flg = 0;
  32.     scanf("%d", &n);
  33.     if(n < 0 || 64 < n){
  34.     	puts("error");
  35.         return(1);
  36.     }
  37.     f(arr, &flg, n, n);
  38.     return(0);
  39. }
  40.  
Success #stdin #stdout 0s 4820KB
comments (?)
stdin 
4
stdout 
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
https://ideone.com/1EStFG
18_308
language:
C (gcc 8.3)
created:
3 years ago
visibility:
secret

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