HDU 2795 Billboard——特殊查询的线段树

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int maxn = 1e5 * 2 + 10;

int h, w, n, date[maxn], segTree[maxn<<2];

void pushup(int root) {
    segTree[root] = max(segTree[root<<1], segTree[root<<1|1]);
}

void build(int L, int R, int root) {
    if (L == R) {
        segTree[root] = w;
        return;
    }
    int mid = (L + R)>>1;
    build(L, mid, root<<1);
    build(mid + 1, R, root<<1|1);
    pushup(root);
}

int query(int L, int R, int root, int val) {
    if (L == R) {
        segTree[root] -= val;
        return L;
    }
    int mid = (L + R)>>1;
    int ans = (segTree[root<<1] >= val) ? query(L, mid, root<<1, val) : query(mid + 1, R, root<<1|1, val);
    pushup(root);
    return ans;
}

int main()
{
    while (scanf("%d %d %d", &h, &w, &n) == 3) {
        if (h > n) {
            h = n;
        }
        build(1, h, 1);
        for (int i = 1; i <= n; i++) {
            int temp; scanf("%d", &temp);
            if (segTree[1] < temp) {
                printf("-1\n");
            }
            else {
                printf("%d\n", query(1, h, 1, temp));
            }
        }
    }
    return 0;
}