二分搜索 POJ 2456 Aggressive cows

题目传送门

 /*
     二分搜索：搜索安排最近牛的距离不小于d
 */
 #include <cstdio>
 #include <algorithm>
 #include <cmath>
 using namespace std;

 const int MAXN = 1e5 + ;
 const int INF = 0x3f3f3f3f;
 int x[MAXN];
 int n, m;

 bool check(int d)   {
     int last = ;
     for (int i=; i<=m-; ++i)    {
         int cur = last + ;
         while (cur <= n && x[cur] - x[last] < d)    cur++;
         if (cur == n + )   return false;
         last = cur;
     }
     return true;
 }

 int main(void)  {       //POJ 2456 Aggressive cows
     //freopen ("POJ_2456.in", "r", stdin);

     while (scanf ("%d%d", &n, &m) == )   {
         for (int i=; i<=n; ++i)    {
             scanf ("%d", &x[i]);
         }

         sort (x+, x++n);
         int l = , r = INF;
         while (l +  < r)   {
             int mid = (l + r) >> ;
             if (check (mid))    l = mid;
             else    r = mid;
         }
         printf ("%d\n", l);
     }

     return ;
 }