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 |
换hash_map也超……In Reply To:O(n^2)都tle, map也这么慢阿。 Posted by:first at 2006-03-25 21:17:42 > #include <iostream> > #include <map> > using namespace std; > > int N; > int num[4000][4]; > map <int, int> sum[2]; > int ans; > map<int, int>::iterator iter; > int main() > { > sum[0].clear(); > sum[1].clear(); > scanf("%d", &N); > int i, j; > for(i = 0; i < N; i ++) > scanf("%d %d %d %d", &num[i][0], &num[i][1], &num[i][2], &num[i][3]); > for(i = 0; i < N; i ++) > for(j = 0; j < N; j ++) > { > sum[0][num[i][0] + num[j][1]] ++; > sum[1][num[i][2] + num[j][3]] ++; > } > > for(iter = sum[0].begin(); iter != sum[0].end(); iter ++) > { > ans += sum[1][-iter->first]*sum[0][iter->first]; > } > 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