把B个投票箱分配到n个城市,每个城市至少一个投票箱,投票箱的容量最小是多少?
求二分区间中满足条件的最小值。
#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
const int MAXN = 2e6 + 10;
int a[MAXN];
int n, b;
bool check(int mid) {
int num = 0;
for (int i = 0; i < n; ++i) {
num += ceil(a[i]*1.0/mid); // 计算一座城市需要多少个箱子
}
if (num <= b) {
// 箱子数比给的少满足条件
return true;
} else {
return false;
}
}
int main() {
while (~scanf("%d%d", &n, &b)) {
if (n == -1 && b == -1) {
break;
}
int maxNum = 0;
for (int i = 0; i < n; ++i) {
scanf("%d", &a[i]);
maxNum = max(maxNum, a[i]);
}
int l = 0;
int r = maxNum;
int ans = 0;
while (l <= r) {
int mid = (l + r) >> 1;
if (check(mid)) {
ans = mid;
r = mid - 1;
} else {
l = mid + 1;
}
}
printf("%d\n", ans);
}
return 0;
}