Compilare: main.cpp: In function 'int main()': main.cpp:13:45: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri2.in", "r", stdin); ^ main.cpp:14:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri2.out", "w", stdout); ^ main.cpp:15:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ++N; ++M; ^ main.cpp:17:53: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(j=2; j<=M; ++j) {scanf("%d", &Map[i][j]); Map[i][j]=-Map[i][j];} ^