POJ 2785 4 Values whose Sum is 0
来源:互联网 发布:领导人媒体形象优化 编辑:程序博客网 时间:2024/05/19 07:27
链接:http://poj.org/problem?id=2785
题意:一组4个数,给出若干组,输出有多少对组合满足四个数之和为0
将四列数并成两列,对两列二分查找
#include <cstdio>#include <algorithm>using namespace std;int t[4010][4];int first2[4000*4000+4],last2[4000*4000+4];int Binsearch(int total,int key) { int l=0,r=total-1; bool flag=0; while(l<=r) { int mid=(l+r)>>1; if(first2[mid]==key) { flag=1; break; } else if(first2[mid]>key) r=mid-1; else l=mid+1; } if(flag) { int sum; for(sum=0; l<total; l++) { if(first2[l]==key) sum++; if(sum && first2[l]!=key) break; } return sum; } return 0;}int main() { int n; while(~scanf("%d",&n)) { int k=0; for(int i=0; i<n; i++) for(int j=0; j<4; j++) scanf("%d",&t[i][j]); for(int i=0; i<n; i++) for(int j=0; j<n; j++) { first2[k]=t[i][0]+t[j][1]; last2[k++]=t[i][2]+t[j][3]; } sort(first2,first2+k); sort(last2,last2+k); int ans=0; for(int i=0; i<k; i++) ans+=Binsearch(k,-last2[i]); printf("%d\n",ans); }}
0 0
- POJ 2785 Values whose Sum is 0
- 4 Values whose Sum is 0 POJ
- 4 Values whose Sum is 0 POJ
- 4 Values whose Sum is 0 POJ
- 4 Values whose Sum is 0 POJ
- POJ 2785 4 Values whose Sum is 0
- POJ 2785 4 Values whose Sum is 0 二分
- POJ 2785:4 Values whose Sum is 0
- POJ 2785(4 Values whose Sum is 0)
- poj 2785 4 Values whose Sum is 0
- poj 2785 4 Values whose Sum is 0 (二分+枚举)
- poj 2785 4 Values whose Sum is 0(hash)
- POJ 2785: 4 Values Whose Sum is 0
- poj 2785 4 Values whose Sum is 0
- POJ 2785 4 Values whose Sum is 0 Hash!
- poj 2785 4 Values whose Sum is 0 哈希
- POJ 2785 4 Values whose Sum is 0(二分)
- POJ 2785 4 Values whose Sum is 0 二分
- Codeforces 625 . A Guest From the Past
- 【训练题】拓扑排序
- Android-常见问题解决方案
- hdu 1394 Minimum Inversion Number(最小逆序数) 线段树/暴力
- ML 14 part2 principal component analysis
- POJ 2785 4 Values whose Sum is 0
- day06__模块特殊变量2
- .net mvc 控制器入门
- 关于android底层的认识
- 第一天
- HDU 2425 Hiking Trip(bfs+优先队列)
- H.264之编码格式-封装成MP4格式-视频流 RTP封包
- Eclipse搭建Java Swing可视化开发环境
- 逆序对