CodeVS 2928 你缺什么 题解

#include <iostream>#include <cstdio>#include <cstdlib>using namespace std;int N;int X[10000+2];bool flag[10000+2];int ans[10000+2];void DFS(int n){    if(n>N){        printf("%d", ans[1]);        for(int i = 2; i<=N; ++i) printf(" %d", ans[i]);        printf("\n");        exit(0);    }    for(int i = 1; i<=N; ++i){        if(!flag[i] && X[ans[n-1]] != X[i]){            ans[n] = i;            flag[i] = true;            DFS(n+1);            flag[i] = false;        }    }}int main(){    scanf("%d", &N);    for(int i = 1; i<=N; ++i) scanf("%d", X+i);    DFS(1);    return 0;}