HDU 4004 The Frog's Games(二分)

题目链接

题意理解的有些问题。

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 using namespace std;
 #define LL __int64
 LL p[];
 int n;
 int judge(int x,int m)
 {
     int pre = ,num = ,i;
     for(i = ;i <= n;i ++)
     {
         if(p[i] - pre <= x)
         ;
         else
         {
             num ++;
             pre = p[i-];
         }
     }
     if(num +  > m)
     return ;
     else
     return ;
 }
 int main()
 {
     int m,i,l;
     LL str,mid,end,minz;
     while(scanf("%d%d%d",&l,&n,&m)!=EOF)
     {
         for(i = ; i < n; i ++)
             scanf("%I64d",&p[i]);
         sort(p,p+n);
         if(n == ||m == )
         {
             printf("%d\n",l);
             continue;
         }
         p[n] = l;
         minz = p[];
         for(i = ;i < n;i ++)
         {
             minz = max(minz,p[i+]-p[i]);
         }
         str = minz;end = l;
         while(str < end)
         {
             mid = (str+end)/;
             if(judge(mid,m) == )
             str = mid + ;
             else
             end = mid;
         }
         printf("%I64d\n",str);
     }
     return ;
 }