Compilare: user.cpp: In function ‘void RemoveNodes()’: user.cpp:56:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k = 0; k < vec[i].size(); k++) { ^ user.cpp: In function ‘int FindPath(int, int, int, int)’: user.cpp:90:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (k = 0; k < out[i].size(); k++) { ^ user.cpp: In function ‘void Solve()’: user.cpp:123:12: warning: unused variable ‘j’ [-Wunused-variable] int i, j, p, k; ^ user.cpp:123:15: warning: unused variable ‘p’ [-Wunused-variable] int i, j, p, k; ^ user.cpp: In function ‘void WriteOutput()’: user.cpp:241:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < out[i].size(); j++) { ^ user.cpp: In function ‘void ReadInput()’: user.cpp:18:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nowhere-zero.in", "r", stdin); ^ user.cpp:19:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:21:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf %lf", &(x[i]), &(y[i])); ^ user.cpp:23:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &i, &j); ^ user.cpp: In function ‘void WriteOutput()’: user.cpp:239:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("nowhere-zero.out", "w", stdout); ^