1到n的全排列(DFS)

#include <stdio.h>

int a[10],book[100],n;

void dfs(int step){
    int i;
    if(step==n+1){
        for(i=1;i<=n;i++)
            printf("%d",a[i]);
        printf("\n");
        
        return;
    }
    
    for(i=1;i<=n;i++){
        if(book[i]==0){
            a[step]=i;
            book[i]=1;
            dfs(step+1);
            book[i]=0;
        }
    }
    return;
}


int main() {
    scanf("%d",&n);
    dfs(1);
    getchar();
    getchar();
    return 0;
}