//http://contest-hunter.org:83/contest/0x10%E3%80%8C%E5%9F%BA%E6%9C%AC%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E3%80%8D%E4%BE%8B%E9%A2%98/1101%20%E7%81%AB%E8%BD%A6%E8%BF%9B%E6%A0%88 #include #include using namespace std; int n,stk[25],top,res[25],len,cnt; void dfs(int x) { if(x==n+1) { cnt++; for(int i=0;i=0;i--) printf("%d",stk[i]); puts(""); if(cnt==20) exit(0); return; } if(top) { res[len++]=stk[--top]; dfs(x); stk[top++]=res[--len]; } stk[top++]=x; dfs(x+1); top--; } int main() { #ifdef local freopen("pro.in","r",stdin); #endif scanf("%d",&n); dfs(1); return 0; }