hdu 5138

参考……！！！！

#include <iostream>

#include <cstdio>

#include <cmath>

#include <cstring>

#include <algorithm>

#include <cstdlib>

#include <stack>

#include <cctype>

#include <string>

#include <malloc.h>

#include <queue>

#include <map>

#include <set>



using namespace std;



const int INF = 0xffffff;

const double esp = 10e-8;

const double Pi = 4 * atan(1.0);

const int maxn =  1000000 + 10;

const long long mod =  1000000007;

const int dr[] = {1,0,-1,0,-1,1,-1,1};

const int dc[] = {0,1,0,-1,1,-1,-1,1};

typedef long long LL;



LL gac(LL a,LL b){

    return b?gac(b,a%b):a;

}

const int hashtable = 1000007;

struct Hash{

    int head[hashtable];

    int _next[maxn];

    long long state[maxn];

    int cnt;

    void init(){

        cnt = 1;

        memset(head,0,sizeof(head));

    }

    bool _find(LL s){

        int h = (s % hashtable+hashtable)%hashtable;

        int u = head[h];

        while(u){

            if(s == state[u])

                return 1;

            u = _next[u];

        }

        return 0;

    }

    bool try_to_insert(LL s){

        int h = (s % hashtable+hashtable)%hashtable;

        _next[cnt] = head[h];

        state[cnt] = s;

        head[h] = cnt;

        cnt++;

        return 0;

    }



};

Hash H1,H2;

inline LL read()

{

    char ch=getchar();LL x=0,f=1;

    while(ch>'9'||ch<'0'){if(ch=='-')f=-1;ch=getchar();}

    while(ch<='9'&&ch>='0'){x=x*10+ch-'0';ch=getchar();}

    return x*f;

}

LL a[maxn];

int main()

{

#ifndef ONLINE_JUDGE

    freopen("inpt.txt","r",stdin);

   // freopen("output.txt","w",stdout);

#endif

    int t;

    scanf("%d",&t);

    for(int cas = 1;cas <= t;cas++){

        int n,k;

        scanf("%d%d",&n,&k);

        H1.init();

        H2.init();

        LL sum = 0;

        bool ok = 0;

        H1.try_to_insert(0);

        H2.try_to_insert(0);

        for(int i = 0;i < n;i++){

            a[i] = read();

        }

        for(int i = n-1;i > -1 && !ok;i--){

            if(ok)

                continue;

            if(i % 2 == 1){

                sum -= a[i];

                if(H2._find(-sum-k)){

                    ok = 1;

                }

            }

            else{

                sum += a[i];

                if(H1._find(sum-k)){

                    ok = 1;

                }

            }

            H1.try_to_insert(sum);

            H2.try_to_insert(-sum);

        }

        printf("Case #%d: %s.\n",cas,ok?"Yes":"No");

    }

    return 0;

}

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