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。。。
1 //STATUS:C++_AC_453MS_1792KB 2 #include <functional> 3 #include <algorithm> 4 #include <iostream> 5 //#include <ext/rope> 6 #include <fstream> 7 #include <sstream> 8 #include <iomanip> 9 #include <numeric> 10 #include <cstring> 11 #include <cassert> 12 #include <cstdio> 13 #include <string> 14 #include <vector> 15 #include <bitset> 16 #include <queue> 17 #include <stack> 18 #include <cmath> 19 #include <ctime> 20 #include <list> 21 #include <set> 22 #include <map> 23 using namespace std; 24 //#pragma comment(linker,"/STACK:102400000,102400000") 25 //using namespace __gnu_cxx; 26 //define 27 #define pii pair<int,int> 28 #define mem(a,b) memset(a,b,sizeof(a)) 29 #define lson l,mid,rt<<1 30 #define rson mid+1,r,rt<<1|1 31 #define PI acos(-1.0) 32 //typedef 33 typedef __int64 LL; 34 typedef unsigned __int64 ULL; 35 //const 36 const int N=100010; 37 const int INF=0x3f3f3f3f; 38 const int MOD=10007,STA=8000010; 39 const LL LNF=1LL<<55; 40 const double EPS=1e-9; 41 const double OO=1e30; 42 const int dx[4]={-1,0,1,0}; 43 const int dy[4]={0,1,0,-1}; 44 const int day[13]={0,31,28,31,30,31,30,31,31,30,31,30,31}; 45 //Daily Use ... 46 inline int sign(double x){return (x>EPS)-(x<-EPS);} 47 template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;} 48 template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;} 49 template<class T> inline T lcm(T a,T b,T d){return a/d*b;} 50 template<class T> inline T Min(T a,T b){return a<b?a:b;} 51 template<class T> inline T Max(T a,T b){return a>b?a:b;} 52 template<class T> inline T Min(T a,T b,T c){return min(min(a, b),c);} 53 template<class T> inline T Max(T a,T b,T c){return max(max(a, b),c);} 54 template<class T> inline T Min(T a,T b,T c,T d){return min(min(a, b),min(c,d));} 55 template<class T> inline T Max(T a,T b,T c,T d){return max(max(a, b),max(c,d));} 56 //End 57 58 struct Node{ 59 int s,id; 60 bool operator < (const Node& a)const { 61 return s!=a.s?s<a.s:id<a.id; 62 } 63 }st[N]; 64 int num[N],sum[N]; 65 int n,m; 66 67 int binary(int l,int r,int tar) 68 { 69 int mid; 70 while(l<r){ 71 mid=(l+r)>>1; 72 if(st[mid].s<=tar)l=mid+1; 73 else r=mid; 74 } 75 return l; 76 } 77 78 int main(){ 79 // freopen("in.txt","r",stdin); 80 int i,j,ans,w; 81 while(~scanf("%d%d",&n,&m)) 82 { 83 sum[0]=0; 84 for(i=1;i<=n;i++){ 85 scanf("%d",&num[i]); 86 sum[i]=((sum[i-1]+num[i])%m+m)%m; 87 st[i].s=sum[i]; 88 st[i].id=i; 89 } 90 sort(st+1,st+n+1); 91 ans=0; 92 for(i=0;i<n && ans<n-i;i++){ 93 w=binary(1,n+1,sum[i]); 94 if(st[w-1].s==sum[i] && st[w-1].id>i)ans=Max(ans,st[w-1].id-i); 95 } 96 97 printf("%d\n",ans); 98 } 99 return 0; 100 }
