扶苏出勤日记 参考代码

#include <bits/stdc++.h>
using namespace std;

typedef long long LL;
const int maxn = 1000000 + 100;
const int Log = 20;
int T, n;
int a[maxn], b[maxn];
int stMax[maxn][Log], mn[maxn];

void init() {
    mn[0] = -1;
    for(int i = 1; i <= n; ++i) {
        mn[i] = ((i & (i - 1)) == 0)? mn[i - 1] + 1: mn[i - 1];
        stMax[i][0] = a[i];
    }
    for(int j = 1; j <= mn[n]; ++j) {
        for(int i = 1; i + (1 << j) - 1 <= n; ++i) {
            stMax[i][j] = max(stMax[i][j - 1], stMax[i + (1 << (j - 1))][j - 1]);
        }
    }
}

int rmqMax(int L, int R) {
    int k = mn[R - L + 1];
    return max(stMax[L][k], stMax[R - (1 << k) + 1][k]);
}

bool judge(LL x) {
    int idx = 1;
    LL leftCoin = 0;
    int bTmp = b[1];
    for (int i = 1; i <= n; ++i) {
        LL xTmp = x;
        if (xTmp <= leftCoin) {
            leftCoin -= xTmp;
            continue;
        }
        xTmp -= leftCoin;
        leftCoin = 0;
        while (idx <= i && xTmp > 0) {
            LL mx = rmqMax(idx, i);
            LL cut = min((xTmp + mx - 1) / mx, (LL) bTmp);
            leftCoin += cut * mx;
            bTmp -= cut;
            if (bTmp == 0) {
                ++idx;
                bTmp = b[idx];
            }
            if (leftCoin <= xTmp) {
                xTmp -= leftCoin;
                leftCoin = 0;
            } else {
                leftCoin -= xTmp;
                xTmp = 0;
            }
        }
        if (xTmp > 0) {
            return false;
        }
    }
    return true;
}

int main() {
#ifdef ExRoc
    freopen("test.txt", "r", stdin);
#endif // ExRoc
    ios::sync_with_stdio(false);

    cin >> T;
    while (T--) {
        cin >> n;
        LL low = 0;
        LL high = 0;
        LL mid;
        for (int i = 1; i <= n; ++i) {
            cin >> a[i];
        }
        init();
        LL mx = rmqMax(1, n);
        for (int i = 1; i <= n; ++i) {
            cin >> b[i];
            high += mx * b[i];
        }
        high /= n;
        ++high;
        while (high - low > 1) {
            mid = (high + low) >> 1;
            if (judge(mid)) {
                low = mid;
            } else {
                high = mid;
            }
        }
        cout << low << endl;
    }

    return 0;
}