HDU-4648 Magic Pen 6 简单题

　　题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=4648

　　求遍前缀和，然后扫描标记下就可以了。。。

//STATUS:C++_AC_453MS_1792KB
#include <functional>
#include <algorithm>
#include <iostream>
//#include <ext/rope>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <numeric>
#include <cstring>
#include <cassert>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <list>
#include <set>
#include <map>
using namespace std;
//#pragma comment(linker,"/STACK:102400000,102400000")
//using namespace __gnu_cxx;
//define
#define pii pair<int,int>
#define mem(a,b) memset(a,b,sizeof(a))
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define PI acos(-1.0)
//typedef
typedef __int64 LL;
typedef unsigned __int64 ULL;
//const
const int N=100010;
const int INF=0x3f3f3f3f;
const int MOD=10007,STA=8000010;
const LL LNF=1LL<<55;
const double EPS=1e-9;
const double OO=1e30;
const int dx[4]={-1,0,1,0};
const int dy[4]={0,1,0,-1};
const int day[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
//Daily Use ...
inline int sign(double x){return (x>EPS)-(x<-EPS);}
template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;}
template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;}
template<class T> inline T lcm(T a,T b,T d){return a/d*b;}
template<class T> inline T Min(T a,T b){return a<b?a:b;}
template<class T> inline T Max(T a,T b){return a>b?a:b;}
template<class T> inline T Min(T a,T b,T c){return min(min(a, b),c);}
template<class T> inline T Max(T a,T b,T c){return max(max(a, b),c);}
template<class T> inline T Min(T a,T b,T c,T d){return min(min(a, b),min(c,d));}
template<class T> inline T Max(T a,T b,T c,T d){return max(max(a, b),max(c,d));}
//End

struct Node{
    int s,id;
    bool operator < (const Node& a)const {
        return s!=a.s?s<a.s:id<a.id;
    }
}st[N];
int num[N],sum[N];
int n,m;

int binary(int l,int r,int tar)
{
    int mid;
    while(l<r){
        mid=(l+r)>>1;
        if(st[mid].s<=tar)l=mid+1;
        else r=mid;
    }
    return l;
}

int main(){
 //   freopen("in.txt","r",stdin);
    int i,j,ans,w;
    while(~scanf("%d%d",&n,&m))
    {
        sum[0]=0;
        for(i=1;i<=n;i++){
            scanf("%d",&num[i]);
            sum[i]=((sum[i-1]+num[i])%m+m)%m;
            st[i].s=sum[i];
            st[i].id=i;
        }
        sort(st+1,st+n+1);
        ans=0;
        for(i=0;i<n && ans<n-i;i++){
            w=binary(1,n+1,sum[i]);
            if(st[w-1].s==sum[i] &&  st[w-1].id>i)ans=Max(ans,st[w-1].id-i);
        }

        printf("%d
",ans);
    }
    return 0;
}