Compilare: user.cpp: In function ‘int main()’: user.cpp:34:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri3.in", "r", stdin); ^ user.cpp:35:47: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri3.out", "w", stdout); ^ user.cpp:39:32: 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:42:81: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d", &v[i].x1, &v[i].y1, &v[i].x2, &v[i].y2, &v[i].value); ^ user.cpp:37:18: warning: ‘M’ may be used uninitialized in this function [-Wmaybe-uninitialized] int i, j, N, M, cells = 0, pos; ^ user.cpp:37:15: warning: ‘N’ may be used uninitialized in this function [-Wmaybe-uninitialized] int i, j, N, M, cells = 0, pos; ^