LightOJ - 1076 Get the Containers(二分)

题目大意：给你N个数字，要起将这N个数字划分成K个区间，并要求每个区间的和的最大值最小

解题思路：最大值最小问题，二分解决

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
typedef long long LL;
const int N = 1000010;

LL v[N];
LL l, r;
int n, m, cas = 1;

void init() {
    scanf("%d%d", &n, &m);
    l = r = 0;
    for (int i = 0; i < n; i++) {
        scanf("%lld", &v[i]);
        l = max(v[i], l);
        r += v[i];
    }
    v[n] = 0;
}

bool judge(LL mid) {
    LL sum = 0;
    int num = 1;
    for (int i = 0; i <= n; i++) {
        if (sum + v[i] > mid) {
            sum = v[i];
            num++;
        }
        else sum += v[i];
    }
    return num <= m;
}

void solve() {
    while (l <= r) {
        LL mid = (l + r) >> 1;
        if (judge(mid)) r = mid - 1;
        else l = mid + 1;
    }
    printf("Case %d: %lld\n", cas++, r + 1);
}

int main() {
    int test;
    scanf("%d", &test);
    while (test--) {
        init();
        solve();
    }
    return 0;
}