ZOJ 1589 dead sor John ~ Floyd algorithm

Both Floyd and Dij can be used for this question, but it is very convenient to use Floyd. It is also the first time to use the Floyd algorithm. I didn't have this idea at first, so I could refer to other people's ideas ..~~~~ (>_< )~~~~

 

# Include <stdio. h> # include <iostream> # include <string. h> using namespace std; int main (void) {int ncases, n, I, j, k; int map [30] [30], mark [30] [30]; cin> ncases; for (int f = 1; f <= ncases; f ++) {memset (map, 0, sizeof (map); memset (mark, 0, sizeof (mark); int flag = 1; cin> n; char s [4]; while (n --) {scanf ("% s", s ); int a, B; char o; a = s [0]-'A' + 1; o = s [1]; B = s [2]-'A' + 1; if (o = '<') map [A] [B] = 1; else Map [B] [a] = 1;} memcpy (mark, map, sizeof (map); for (k = 1; k <= 28; k ++) for (I = 1; I <= 28; I ++) for (j = 1; j <= 28; j ++) map [I] [j] = map [I] [j] | (map [I] [k] & map [k] [j]); // here the Floyd is cleverly deformed .. At least I think this is a weak dish. Aha printf ("Case % d: \ n", f); for (I = 1; I <= 28; I ++) for (j = 1; j <= 28; j ++) if (map [I] [j]) &! Mark [I] [j]) {printf ("% c <% c \ n", I + 'a'-1, j + 'a'-1 ); flag = 0;} if (flag) printf ("NONE \ n") ;}return 0 ;}