nyoj 545 Metric Matrice
Metric Matrice
时间限制:1000 ms | 内存限制:65535 KB
难度:1
描述
Given as input a square distance matrix, where a[i][j] is the distance between point i and point j, determine if the distance matrix is "a metric" or not.
A distance matrix a[i][j] is a metric if and only if
1. a[i][i] = 0
2, a[i][j]> 0 if i != j
3. a[i][j] = a[j][i]
4. a[i][j] + a[j][k] >= a[i][k] i ¹ j ¹ k
输入
The first line of input gives a single integer, 1 ≤ N ≤ 5, the number of test cases. Then follow, for each test case,
* Line 1: One integer, N, the rows and number of columns, 2 <= N <= 30
* Line 2..N+1: N lines, each with N space-separated integers
(-32000 <=each integer <= 32000).
输出
Output for each test case , a single line with a single digit, which is the lowest digit of the possible facts on this list:
* 0: The matrix is a metric
* 1: The matrix is not a metric, it violates rule 1 above
* 2: The matrix is not a metric, it violates rule 2 above
* 3: The matrix is not a metric, it violates rule 3 above
* 4: The matrix is not a metric, it violates rule 4 above
样例输入
2
4
0 1 2 3
1 0 1 2
2 1 0 1
3 2 1 0
2
0 3
2 0
样例输出
0
3
#include<stdio.h> #include<string.h> int x[35][35]; void slove(int n) { for(int i=0;i<n;++i) { if(x[i][i]!=0) { printf("1\n"); return; } } for(int i=0;i<n;++i) { for(int j=0;j<n;++j) { if(i!=j&&x[i][j]<=0) { printf("2\n"); return; } } } for(int i=0;i<n;++i) { for(int j=0;j<n;++j) { if(i!=j&&x[i][j]!=x[j][i]) { printf("3\n"); return; } } } for(int i=0;i<n;++i) { for(int j=0;j<n;++j) { for(int k=0;k<n;++k) { if(i!=j&&j!=k&&i!=k&&x[i][j]+x[j][k]<x[i][k]) { printf("4\n"); return ; } } } } printf("0\n"); } int main() { int t,n; scanf("%d",&t); while(t--) { scanf("%d",&n); for(int i=0;i<n;++i) { for(int j=0;j<n;++j) { scanf("%d",&x[i][j]); } } slove(n); } return 0; }