题解 | 不想做二分题

二分答案，显然是否能够击杀和攻击顺序无关

首先让小红打完所有伤害，然后让队友 2 从左到右贪心来做到尽量多双击，最后看队友 1 和队友 2 剩余的技能是否够全部击杀

#include <iostream>
#include <vector>
using namespace std;

const int MAXI = 1e9;

int n;
vector<int> a;

vector<int> a2;
bool Check(int mid) {
    a2 = a;
    for (auto& x : a2) {
        x = max(x - mid, 0);
    }
    int rest = mid;
    for (int i = 1; i < n; i++) {
        int can = min(a2[i - 1], a2[i]);
        if (can >= rest) {
            a2[i - 1] -= rest;
            a2[i] -= rest;
            break;
        }
        rest -= can;
        a2[i - 1] -= can;
        a2[i] -= can;
    }
    int sum = -rest;
    for (const auto& x : a2) {
        sum += x;
        if (sum > mid) {
            return false;
        }
    }
    return true;
}

void Solve() {
    cin >> n;
    a.resize(n);
    for (auto& x : a) {
        cin >> x;
    }
    int l = 1;
    int r = MAXI;
    int mid;
    while (l < r) {
        mid = (l + r) >> 1;
        if (Check(mid)) {
            r = mid;
            continue;
        }
        l = mid + 1;
    }
    cout << l;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    Solve();
    return 0;
}
// 64 位输出请用 printf("%lld")