hdu_2795,线段树，单点更新

#include<iostream>
#include<cstdio>
#include<cstring>
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
using namespace std;
const int maxn=222222;
int seq[maxn<<2];
int h,w;
void pushUp(int rt)
{
    seq[rt]=max(seq[rt<<1],seq[rt<<1|1]);
}
void build(int l,int r,int rt)
{
    seq[rt]=w;
    if(l==r)
    {
        return;
    }
    int m=(r+l)>>1;
    build(lson);
    build(rson);
}
int query(int d,int l,int r,int rt)
{
    int ret=-1;
    if(l==r)
    {
        seq[rt]-=d;
        return l;
    }
    int m=(r+l)>>1;
    if(seq[rt<<1]>=d) ret=query(d,lson);
    else ret=query(d,rson);
    pushUp(rt);
    return ret;
}
int main()
{
    int n;
    while(scanf("%d%d%d",&h,&w,&n)!=EOF)
    {
        int a;
        if(h>n) h=n;
        memset(seq,0,sizeof(seq));
        build(0,h-1,1);
        for(int i=0;i<n;i++)
        {
            scanf("%d",&a);
            if(seq[1]<a) printf("-1
");
            else
            printf("%d
",query(a,0,h-1,1)+1);
        }
    }
    return 0;
}