HDU - 4334 Trouble
Hassan is in trouble. His mathematics teacher has given him a very difficult problem called 5-sum. Please help him.
The 5-sum problem is defined as follows: Given 5 sets S_1,...,S_5 of n integer numbers each, is there a_1 in S_1,...,a_5 in S_5 such that a_1+...+a_5=0?InputFirst line of input contains a single integer N (1≤N≤50). N test-cases follow. First line of each test-case contains a single integer n (1<=n<=200). 5 lines follow each containing n integer numbers in range [-10^15, 1 0^15]. I-th line denotes set S_i for 1<=i<=5.OutputFor each test-case output "Yes" (without quotes) if there are a_1 in S_1,...,a_5 in S_5 such that a_1+...+a_5=0, otherwise output "No".Sample Input
2 2 1 -1 1 -1 1 -1 1 -1 1 -1 3 1 2 3 -1 -2 -3 4 5 6 -1 3 2 -4 -10 -1
Sample Output
No Yes
我是将钱两个和哈希，再计算后三个和哈希匹配。
1 #include <cstdio> 2 #include <iostream> 3 #include <cstring> 4 #include <algorithm> 5 using namespace std; 6 7 const int mod=401704; 8 long long a[5][210],Hash[mod]; 9 bool color[mod]; 10 11 int judge(long long x) 12 { 13 int s=x%mod; 14 if(s<0) s+=mod; 15 while(color[s]&&Hash[s]!=x) 16 s=(s+1)%mod; 17 return s; 18 } 19 20 int main() 21 { 22 int T, n; 23 cin >> T; 24 while(T--) 25 { 26 scanf("%d",&n); 27 memset(color,0,sizeof(color)); 28 for(int i=0; i<5; i++) 29 for(int j=0; j<n; j++) 30 scanf("%lld",&a[i][j]); 31 for(int i=0; i<n; i++) 32 for(int j=0; j<n; j++) 33 { 34 long long sum=-(a[0][i]+a[1][j]); 35 int h=judge(sum); 36 color[h]=1; 37 Hash[h]=sum; 38 } 39 bool ok=false; 40 for(int i=0; i<n&&!ok; i++) 41 for(int j=0; j<n&&!ok; j++) 42 for(int k=0; k<n&&!ok; k++) 43 { 44 long long sum=a[2][i]+a[3][j]+a[4][k]; 45 int h=judge(sum); 46 if(color[h]) 47 { 48 ok=true; break; 49 } 50 } 51 if(ok) printf("Yes\n"); 52 else printf("No\n"); 53 } 54 return 0; 55 }
