Compilare: user.cpp: In function ‘int main()’: user.cpp:40:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[r].size(); i++) ^ user.cpp:50:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < invn.size(); i++) ^ user.cpp:76:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[0].size(); i++) ^ user.cpp:15:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, a, b, c, r; ^ user.cpp:16:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.in", "r", stdin); ^ user.cpp:17:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxflow.out", "w", stdout); ^ user.cpp:18:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:21:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &a, &b, &c); ^