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=;
 const int INF=0x3f3f3f3f;
 const int MOD=,STA=;
 const LL LNF=1LL<<;
 const double EPS=1e-;
 const double OO=1e30;
 const int dx[]={-,,,};
 const int dy[]={,,,-};
 const int day[]={,,,,,,,,,,,,};
 //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)>>;
         if(st[mid].s<=tar)l=mid+;
         else r=mid;
     }
     return l;
 }

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

         printf("%d\n",ans);
     }
     return ;
 }