func_code_string: #include <bits/stdc++.h>   #pragma comment(linker,  /STACK:1024000000,1024000000 )   using namespace std;   const double pi = acos(-1);   const double e = exp(1);   const int INF = 0x3f3f3f3f;   const int MOD = 1e9 + 7;   template <typename T>   inline void read(T &x) {     T ans = 0;     char last =    , ch = getchar();     while (ch <  0  || ch >  9 ) last = ch, ch = getchar();     while (ch >=  0  && ch <=  9 ) ans = ans * 10 + ch -  0 , ch = getchar();     if (last ==  - ) ans = -ans;     x = ans;   }   const int maxn = 1000 + 10;   char str[maxn];   int vis[maxn];   int main() {     while (~scanf( %s , str)) {       memset(vis, 0, sizeof(vis));       int flag = 1;       for (int i = 0; str[i]; i++) {         for (int j = 0; j < str[i] -  a ; j++) {           if (!vis[j]) {             flag = 0;             break;           }         }         if (!flag) break;         vis[str[i] -  a ] = 1;       }       puts(flag ?  YES  :  NO );     }     return 0;   }   