| ||||||||||
| Online Judge | Problem Set | Authors | Online Contests | User | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Web Board Home Page F.A.Qs Statistical Charts | Current Contest Past Contests Scheduled Contests Award Contest | |||||||||
放心大胆地开数组吧...#include<iostream>
using namespace std;
#define maxn 5000
#define bignum 19999999
#define Inf 219901124
int n,ans,a[4][maxn],hash[bignum+10],s[bignum+10];
void Init() {
scanf("%d",&n);
for (int i=0; i<n; i++)
for (int j=0; j<4; j++) scanf("%d",&a[j][i]);
fill_n(hash,bignum,Inf);
}
int Hash(int h) {
h%=bignum;
return (h>0)?h:h+bignum;
}
void Add(int num,int flag) {
if (flag) num=-num;
int h=Hash(num);
while (hash[h]!=Inf && hash[h]!=num) {
h++;
if (h==bignum) h=0;
}
if (flag) ans+=s[h];
else hash[h]=num,s[h]++;
}
void Work() {
for (int i=0; i<n; i++)
for (int j=0; j<n; j++)
Add(a[0][i]+a[1][j],0);
for (int i=0; i<n; i++)
for (int j=0; j<n; j++)
Add(a[2][i]+a[3][j],1);
}
int main() {
Init();
Work();
printf("%d\n",ans);
return 0;
}
Followed by: Post your reply here: |
All Rights Reserved 2003-2013 Ying Fuchen,Xu Pengcheng,Xie Di
Any problem, Please Contact Administrator