题目链接

Drying POJ - 3104

思路

$$ 二分 $$

时间复杂度

$$ O(Nlog(max(a_i))) $$

代码

#include <cstdio>
#include <algorithm>

using namespace std;

const int MAXN = 1e5 + 10;
int n, m;
int a[MAXN];

bool check(int mid) {
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        int x = a[i] - mid;
        if (x < 0) {
            x = 0;
        }

        if (m != 1) {
            ans += x / (m - 1);
            if (x % (m - 1) != 0) {
                ans++;
            }
        } else {
            if (x > 0) {
                return false;
            }
        }

        if (ans > mid) {
            return false;
        }
    }
    return true;
}

int main() {
    scanf("%d", &n);// don't forget &
    for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);// don't forget &
    }
    scanf("%d", &m);// don't forget &
    int l = 1, r = 1e9, ans = r;
    while (l <= r) {
        int mid = (l + r) >> 1;
        if (check(mid)) {
            ans = mid;
            r = mid - 1;
        } else {
            l = mid + 1;
        }
    }
    printf("%d", ans);
    return 0;
}