Stuff

#include <stdio.h> 
#include <stdlib.h> 
#define N 4 

void perm(int*, int); 

int main(void) { 
    int num[N+1], i; 

    for(i = 1; i <= N; i++) 
        num[i] = i; 

    perm(num, 1); 

    return 0; 
} 

void perm(int* num, int i) { 
    int j, k, tmp; 

    if(i < N) { 
        for(j = i; j <= N; j++) { 
            tmp = num[j]; 
            // &#26059;&#36681;&#35442;&#21312;&#27573;&#26368;&#21491;&#37002;&#25976;&#23383;&#33267;&#26368;&#24038;&#37002; 
            for(k = j; k > i; k--) 
                num[k] = num[k-1]; 
            num[i] = tmp; 

            perm(num, i+1); 

            // &#36996;&#21407; 
            for(k = i; k < j; k++) 
                num[k] = num[k+1]; 
            num[j] = tmp; 
        } 
    } 
    else {  // &#39023;&#31034;&#27492;&#27425;&#25490;&#21015; 
        for(j = 1; j <= N; j++) 
            printf("%d ", num[j]); 
        printf("\n"); 
    } 
}