network.cpp: In function 'int _ping(int, int)':
network.cpp:7:29: error: 'i' was not declared in this scope
7 | return (u == v ? -1 : ping(i, j));
| ^
network.cpp:7:32: error: 'j' was not declared in this scope
7 | return (u == v ? -1 : ping(i, j));
| ^
grader.c: In function 'int main()':
grader.c:48:11: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
48 | scanf ("%d%d%d%d", &N, &a, &b, &M);
| ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
grader.c:51:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
51 | scanf("%d", &distance[u][v]);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~~