Compilare: user.c: In function ‘main’: user.c:52:3: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(ult, -1, sizeof ult); ^ user.c:52:3: warning: incompatible implicit declaration of built-in function ‘memset’ [enabled by default] user.c:50:9: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d%d%d", &n, &m, &s, &d); ^ user.c:54:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d%d%d", &x, &y, &z, &t); ^