hihoCoder #1443 : Push Button I ( DFS

题目链接: https://hihocoder.com/problemset/problem/1443

题意:

直接暴力枚举即可, 因为要防止重复,所有我们需要搜索的时候 每个小块内 从小到大的进行搜索

/***********************************************
Author        :Yishui
Created Time  :2018年10月16日 星期二 09时13分52秒
File Name     :B.cpp
************************************************/
#include 
using namespace std;

#define cpp_io() {ios::sync_with_stdio(false); cin.tie(NULL);}
#define rep(i,a,n) for (int i=a;i
#define repp(i,a,n) for (int i=a;i<=n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define CLR(a,b) memset(a,(b),sizeof(a))
#define all(x) (x).begin(),(x).end()
#define SZ(x) ((int)(x).size())
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ls o<<1
#define rs o<<1|1
typedef long long ll;
typedef vector<int> VI;
const int MAXN = (int)2e5+10;
const int INF = 0x3f3f3f3f;
const int mod = (int)1e9+7;
const ll INFF = (ll) 0x3f3f3f3f3f3f3f3f;

void F() {
#ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
    freopen("out.txt","w",stdout);
#endif
}

/*-----------------------------------------------------------*/
bool vis[100];
char s[100];
int n;
void dfs(int k, int len) {
	if(k==n) {
		s[len]='\0'; cout<<s+1<<"\n";
		return ;
	}

	if(s[len-1]!='-') {
		s[len]='-';
		dfs(k,len+1);
	}

	repp(i,1,n) {
		if(vis[i]) continue;
		if(s[len-1]=='-' || s[len-1]<(i+'0')) {
			s[len]=(i+'0');
			vis[i]=true;
			dfs(k+1, len+1);
			vis[i]=false;
		}
	}
}
int main(){
	cin>>n;
	s[0]='-';
	dfs(0, 1);
    return 0;
}