Compilare: user.c: In function ‘calc’: user.c:11:3: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(tr, 0, sizeof tr); ^ user.c:11:3: warning: incompatible implicit declaration of built-in function ‘memset’ [enabled by default] user.c: In function ‘main’: user.c:41:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d", &n, &m); ^ user.c:44:13: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &nr[i][j]); ^