int htoi(char s[])...{ int i, n; n = 0; for(i = 2; (s[i] >= '0' && s[i] <= '9') || (s[i] >= 'a' && s[i] <= 'f') || (s[i] >= 'A' && s[i] <= 'F'); ++i) if(s[i] >= '0' && s[i] <= '9') n = 16 * n + (s[i] - '0'); else if(s[i] >= 'a' && s[i] <= 'f') n = 16 * n + (s[i] - 'a') + 10; else n = 16 * n + (s[i] - 'A') + 10; return n;}