HDU 2795 Billboard 线段树

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Billboard

Time Limit: 20000/8000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 18927    Accepted Submission(s): 7920


Problem Description
At the entrance to the university, there is a huge rectangular billboard of size h*w (h is its height and w is its width). The board is the place where all possible announcements are posted: nearest programming competitions, changes in the dining room menu, and other important information.

On September 1, the billboard was empty. One by one, the announcements started being put on the billboard.

Each announcement is a stripe of paper of unit height. More specifically, the i-th announcement is a rectangle of size 1 * wi.

When someone puts a new announcement on the billboard, she would always choose the topmost possible position for the announcement. Among all possible topmost positions she would always choose the leftmost one.

If there is no valid location for a new announcement, it is not put on the billboard (that's why some programming contests have no participants from this university).

Given the sizes of the billboard and the announcements, your task is to find the numbers of rows in which the announcements are placed.
 

Input
There are multiple cases (no more than 40 cases).

The first line of the input file contains three integer numbers, h, w, and n (1 <= h,w <= 10^9; 1 <= n <= 200,000) - the dimensions of the billboard and the number of announcements.

Each of the next n lines contains an integer number wi (1 <= wi <= 10^9) - the width of i-th announcement.
 

Output
For each announcement (in the order they are given in the input file) output one number - the number of the row in which this announcement is placed. Rows are numbered from 1 to h, starting with the top row. If an announcement can't be put on the billboard, output "-1" for this announcement.
 

Sample Input
3 5 524333
 

Sample Output
1213-1
 
题意:有一个w*h的广告牌 在上面贴长度为x宽为1的广告 每次贴时都尽量靠上靠左
不会覆盖到之前已经贴好的 输入广告长度 输出它所贴在的行数
定义数组tree[maxn<<2] 记录每行广告剩余的长度

//hdu 2795 Billboard 线段树#include <iostream>#include <stdio.h>#include <string.h>using namespace std;#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1int a,b,n;const int maxn=200000;int tree[maxn<<2];//记录当前剩余的最大空间 void pushup(int rt){tree[rt]=max(tree[rt<<1],tree[rt<<1|1]);} void build(int l,int r,int rt){tree[rt]=b;if(l==r){return ;}int m=(l+r)>>1;build(lson);build(rson);pushup(rt);}void update(int t,int l,int r,int rt){if(t>tree[rt])//剩余长度比广告小 不能贴{printf("-1\n");return;}if(l==r)//找到了可以贴的位置 {printf("%d\n",r);tree[rt]-=t;return ;}int m=(l+r)>>1;if(t<=tree[rt<<1]) update(t,lson);else update (t,rson);pushup(rt);}int main(){std::cin.tie(false);    ios::sync_with_stdio(false);while(~scanf("%d%d%d",&a,&b,&n)){int p,k;memset(tree,0,sizeof(tree));build(1,p=a<n?a:n,1);while(n--){scanf("%d",&k);update(k,1,p,1);}}return 0;}


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