「POJ 2456」Aggressive cows

#include <stdio.h>
#include <algorithm>
#include <iostream>
using namespace std;
char ch_buffer;
bool signum;
inline void readInt(int &l) {
    l = 0;
    do
        ch_buffer = getchar();
    while ((ch_buffer < '0' || ch_buffer > '9') && ch_buffer != '0' &&
           ch_buffer != '-');
    if (ch_buffer == '-') ch_buffer = getchar(), signum = true;
    while (ch_buffer <= '9' && ch_buffer >= '0')
        l = (l << 3) + (l << 1) + ch_buffer - '0', ch_buffer = getchar();
    if (signum) l = -l, signum = false;
}
#define MAX_N 100005
#define INF 0x7fffffff
int x[MAX_N];
int n, c;
inline bool check(int m) {
    int last = 0;
    for (int i = 1; i < c; i++) {
        /*当前的牛舍位置*/
        int cur = last + 1;
        while (cur < n && x[cur] - x[last] < m) cur++;
        /*只放下第一头牛，无法放下第二头牛，使二者的距离大于等于m*/
        if (cur == n) return false;
        last = cur;
        /*把第i头牛放在编号为cur的牛舍里*/
    }
    return true;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    readInt(n), readInt(c);
    for (int i = 0; i < n; i++) readInt(x[i]);
    sort(x, x + n);
    int l = 0, r = INF;
    for (int i = 0; i < 100; i++) {
        int m = (l + r) >> 1;
        if (check(m))
            l = m;
        else
            r = m;
    }
    cout << l << endl;
    return 0;
}