CodeForces 484B 数学 Maximum Value

很有趣的一道题，题解戳这。

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;

 const int maxn =  + ;
 const int maxm =  + ;

 int a[maxn], f[maxm];

 int main()
 {
     int n; scanf("%d", &n);
     for(int i = ; i < n; i++) scanf("%d", a + i);
     sort(a, a + n);
     n = unique(a, a + n) - a;

     int M = a[n-];
     for(int i = ; i < n; i++)
         for(int j = a[i] + ; j <= a[i+]; j++) f[j] = a[i];

     int ans = ;
     for(int i = ; i < n; i++)
     {
         for(int j = a[i] * ; j <= M; j += a[i])
         {
             ans = max(ans, f[j] % a[i]);
         }
         ans = max(ans, M % a[i]);
     }
     printf("%d\n", ans);

     return ;
 }

代码君