Compilare: user.c: In function ‘main’: user.c:21:3: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration] memset(cnt, 0, sizeof(cnt)); ^ user.c:21:3: warning: incompatible implicit declaration of built-in function ‘memset’ [enabled by default] user.c:14:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(FIN, "r", stdin); ^ user.c:15:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(FOUT, "w", stdout); ^ user.c:17:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %s", &N, &C, S); ^