标签：orm scanf ++ string cti ide col bsp iostream
个人心得：周测题目，一题没出，难受得一批。这个题目做了一个半小时还是无限WR，虽然考虑到了二分答案这个点上面了，
奈何二分比较差就想用自己的优化，虽然卡在了a=k*b+c，这里但是后面结束了这样解决还是超时了，看了一下网上的hash，思想一样
但是却优化了很多，服气
题目：
You are given a sequence a consisting of n integers. Find the maximum possible value of (integer remainder of ai divided by aj), where 1?≤?i,?j?≤?n and ai?≥?aj.
Input
The first line contains integer n — the length of the sequence (1?≤?n?≤?2·105).
The second line contains n space-separated integers ai (1?≤?ai?≤?106).
Output
Print the answer to the problem.
Example
3
3 4 5
2
1 #include<iostream> 2 #include<cstdio> 3 #include<cmath> 4 #include<cstring> 5 #include<iomanip> 6 #include<algorithm> 7 using namespace std; 8 #define inf 1<<29 9 #define infa 2000000+10 10 #define nu 50005 11 int n,m; 12 int book[infa]; 13 int main() 14 { 15 scanf("%d",&n); 16 memset(book,-1,sizeof(book)); 17 int maxnum; 18 for(int i=0;i<n;i++){ 19 scanf("%d",&m); 20 book[m]=m; 21 } 22 for(int i=1;i<infa; i++) 23 if(book[i]!=i) 24 { 25 book[i]=book[i-1]; 26 } 27 int sum=0; 28 for(int i=1;i<infa;i++) 29 { 30 if(book[i]==i) 31 { 32 for(int j=i*2-1;j<infa;j+=i) 33 sum=max(sum,book[j]%i); 34 } 35 } 36 cout<<sum<<endl; 37 return 0; 38 }
CodeForces - 484BMaximum Value（hash优化）
标签：orm scanf ++ string cti ide col bsp iostream
原文地址：http://www.cnblogs.com/blvt/p/7867993.html
