Compilare: user.cpp: In function ‘int main()’: user.cpp:43:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i1 = 0; i1 < v[i].v.size(); i1++) ^ user.cpp:50:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i2 = 0; i2 < v[x].v.size(); i2++) ^ user.cpp:58:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i3 = 0; i3 < v[y].v.size(); i3++) ^ user.cpp:26:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tribes.in", "r", stdin); ^ user.cpp:27:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tribes.out", "w", stdout); ^ user.cpp:28:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &k); ^ user.cpp:31:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i].trib); ^ user.cpp:36:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^