[ An Ac a Day ^_^ ] HihoCoder 1249 Xiongnu's Land 线性扫描

 1 #include<stdio.h>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<math.h>
 5 #include<string.h>
 6 #include<string>
 7 #include<map>
 8 #include<set>
 9 #include<vector>
10 #include<queue>
11 #define M(a,b) memset(a,b,sizeof(a))
12 using namespace std;
13 typedef long long ll;
14 const int inf=0x3f3f3f;
15 const int maxn=1e6+10;
16 ll line[maxn];
17 int main(){
18     int T;
19     scanf("%d",&T);
20     while(T--){
21         int sq;
22         scanf("%d",&sq);
23         int n;
24         scanf("%d",&n);
25         int x,y,w,h;
26         M(line,0);
27         ll sum=0;
28         for(int i=0;i<n;i++){
29             scanf("%d%d%d%d",&x,&y,&w,&h);
30             for(int j=x;j<x+w;j++){ //将二维的图转化成一维的线 使时间复杂度达到线性时间O(n)
31                 line[j]+=h;
32                 sum+=h;
33             }
34         }
35         sum++;
36         sum/=2;
37         ll cal=0;
38         for(int i=0;i<=sq;i++){ //扫描
39             cal+=line[i];
40             if(cal>=sum){ //已经符合题意
41                 i++;
42                 while(line[i]==0&&i<sq) i++; //试探着继续扫
43                 printf("%d\n",i);
44                 break;
45             }
46         }
47     }
48     return 0;
49 }
50 /*
51 
52 2
53 1000
54 2
55 1 1 2 1
56 5 1 2 1
57 1000
58 1
59 1 1 2 1
60 
61 */