【HDOJ】2795 Billboard

线段树。注意h范围（小于等于n）。

#include <stdio.h>
#include <string.h>

#define MAXN 200005
#define lson l, mid, rt<<1
#define rson mid+1, r, rt<<1|1
#define mymax(x, y) (x>y) ? x:y

int nums[MAXN<<2];
int h, w;

void PushUP(int rt) {
    nums[rt] = mymax(nums[rt<<1], nums[rt<<1|1]);
}

void build(int l, int r, int rt) {
    int mid;
    nums[rt] = w;

    if (l == r)
        return ;

    mid = (l+r)>>1;
    build(lson);
    build(rson);
}

int query(int wi, int l, int r, int rt) {
    int mid, ret;

    if (l == r) {
        nums[rt] -= wi;
        return l;
    }
    mid = (l+r)>>1;

    if (nums[rt<<1] >= wi)
        ret = query(wi, lson);
    else
        ret = query(wi, rson);

    PushUP(rt);
    return ret;
}

int main() {
    int n, wi;

    while (scanf("%d%d%d", &h, &w, &n) != EOF) {
        if (h > n)
            h = n;      // h < n
        build(1, h, 1);
        while (n--) {
            scanf("%d", &wi);
            if (nums[1] < wi)
                printf("-1
");
            else
                printf("%d
", query(wi, 1, h, 1));
        }
    }

    return 0;
}