Compilare: main.cpp:5:0: warning: ignoring #pragma optimize GCC [-Wunknown-pragmas] #pragma optimize GCC("O3") main.cpp: In function 'int main()': main.cpp:93:37: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d %d", &n, &m) ; ^ main.cpp:96:54: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &mat[i][j]) ; ^