Compilare: user.c: In function ‘dist2d’: user.c:23:5: warning: implicit declaration of function ‘exit’ [-Wimplicit-function-declaration] exit(1); ^ user.c:23:5: warning: incompatible implicit declaration of built-in function ‘exit’ [enabled by default] user.c: In function ‘main’: user.c:30:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d%d", &n, &m, &k); ^ user.c:33:13: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &ma[i][j]); ^ user.c:39:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d%lf", &x[i], &y[i], &r[i]); ^