Compilare: user.cpp: In function ‘int main()’: user.cpp:83:9: warning: variable ‘c’ set but not used [-Wunused-but-set-variable] int r, c, nr3 = 0, nr1 = 0; ^ user.cpp:75:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("puzzle2.in", "r", stdin); ^ user.cpp:76:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("puzzle2.out", "w", stdout); ^ user.cpp:77:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:79:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp: In function ‘void oneLine()’: user.cpp:22:18: warning: ‘v’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(!used[l[v][0]]) ^