HDU 2848 Number Cutting Game（博弈思想 + dfs）题解

思路：dfs找先手必胜的情况是否存在

代码：

#include<stack>
#include<vector>
#include<queue>
#include<set>
#include<cstring>
#include<string>
#include<sstream>
#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#define ll long long
#define ull unsigned long long
using namespace std;
const int maxn = +;
const int seed = ;
const int MOD = ;
const int INF = 0x3f3f3f3f;
ll k;
ll fac[];
int dfs(ll n,ll times,ll sum){
    if(times < k -  && n == ) return ;
    if(times == k - ){
        if(dfs(sum + n,,))
            return ;
        return ;
    }
    for(int i = ;n >= fac[i];i++){ //cut the number
        if(dfs(n / fac[i],times + ,sum + n % fac[i])){
            return ;
        }
    }
    return ;
}
int main(){
    ll n;
    fac[] = ;
    for(int i = ;i <= ;i++)
        fac[i] = fac[i - ] * ;
    while(~scanf("%lld%lld",&n,&k)){
        printf("%d\n",dfs(n,,));
    }
    return ;
}