1 #include <cstdio> 2 #include <cstring> 3 #include <cstdlib> 4 #include <algorithm> 5 using namespace std; 6 7 #define MAXN 150 8 int n; //十字路口的数量 9 int m; //路的个数 10 int map[MAXN][MAXN]; 11 int x[MAXN], y[MAXN]; 12 int mark[MAXN]; 13 14 int search(int a) 15 { 16 for (int i = 1; i <= n; i++) 17 { 18 if (map[a][i] && !mark[i]) 19 { 20 mark[i] = 1; 21 if (y[i] == 0 || search(y[i])) 22 { 23 x[a] = i; 24 y[i] = a; 25 return a; 26 } 27 } 28 } 29 return 0; 30 } 31 32 int main() 33 { 34 int t; 35 scanf("%d", &t); 36 while (t--) 37 { 38 memset(map, 0, sizeof(map)); 39 memset(mark, 0, sizeof(mark)); 40 scanf("%d %d", &n, &m); 41 for (int i = 0; i < m; i++) 42 { 43 int a, b; 44 scanf("%d %d", &a, &b); 45 if (map[a][b] == 0) 46 map[a][b] = 1; 47 } 48 49 int ans1 = 0; 50 memset(x, 0, sizeof(x)); 51 memset(y, 0, sizeof(y)); 52 53 for (int i = 1; i <= n; i++) 54 { 55 if (x[i] == 0) 56 { 57 memset(mark, 0, sizeof(mark)); 58 if (search(i)) 59 ans1++; 60 } 61 } 62 printf("%d ", n - ans1); 63 } 64 //system("pause"); 65 return 0; 66 }