Compilare: user.c: In function ‘main’: user.c:18:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d%d%d", &n, &m, &k ) ; ^ user.c:22:14: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d", &mat2[i][j] ) ; ^ user.c:25:10: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf (fin, "%d%d%d%d", &x1, &y1, &x2, &y2 ) ; ^