Compilare: main.c: In function 'readmatrix': main.c:24:4: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fp, "%d ", &A[i][j]); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c: In function 'main': main.c:100:2: warning: ignoring return value of 'fscanf', declared with attribute warn_unused_result [-Wunused-result] fscanf(fp, "%d %d", &N, &M); ^~~~~~~~~~~~~~~~~~~~~~~~~~~