Compilare: user.c: In function ‘v’: user.c:23:9: warning: implicit declaration of function ‘isalpha’ [-Wimplicit-function-declaration] else if (isalpha(m[j])) ^ user.c:18:8: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (verif[i][j] == -1) ^ user.c: In function ‘main’: user.c:61:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d",&n); ^