http://poj.org/problem?id=3258
题意:一条长度为L得河道,有除了终点起点外有两颗石子,还有n个石子,要去掉m个石子,使得石子间长度最最小值要最大
思路:各种纠结就不说了,困惑的是第二十一行为什么要加个等号,加了不久说明那个距离也不能存在啊。。。
#include <iostream>
#include <algorithm>
using namespace std;
int a[50002];
int L,n,m;
int getAns(int l, int r){
if (l == r) return l;
int mid = (l+r) / 2;
int dmin = (1<<30)-1;
int index = 0;
int cut = 0;
for (int i = 1; i <= n+1; i++){
if (cut == m) {
if (a[i]-a[index] < dmin)
dmin = a[i]-a[index];
index = i;
continue;
}
if (a[i]-a[index] <= mid){
cut++;
}else{
index = i;
}
}
if (cut < m) return getAns(mid+1,r);
if (dmin <= mid) return getAns(l,mid);
return getAns(mid+1,r);
}
int main(){
cin >> L >> n >> m;
a[0] = 0; a[n+1] = L;
for (int i = 1; i <= n; i++){
cin >> a[i];
}
sort(a+1,a+n+1);
int min = (1 << 30)-1;
for (int i = 1; i<= n+1; i++){
if (a[i]-a[i-1] < min) min = a[i] - a[i-1];
}
cout << getAns(min, L)<< endl;
}