C++ code to check string is diverse or not

Suppose we have a string S with n lowercase letters. A string is called diverse if it has consecutive letters of the English alphabet and each letter occurs exactly once. (letters 'a' and 'z' are not adjacent). We have to check whether it is diverse or not.

So, if the input is like S = "fced", then the output will be True.

Steps

To solve this, we will follow these steps −

sort the array S
flag := 1
for initialize i := 1, when i < size of S and flag is non-zero,
update (increase i by 1), do:
   if S[i] - S[i - 1] is not equal to 1, then:
      flag := 0
return (if flag is non-zero, then true, otherwise false)

Example

Let us see the following implementation to get better understanding −

#include <bits/stdc++.h>
using namespace std;
bool solve(string S){
   sort(S.begin(), S.end());
   int flag = 1;
   for (int i = 1; i < S.size() && flag; i++)
      if (S[i] - S[i - 1] != 1)
         flag = 0;
   return flag ? true : false;
}
int main(){
   string S = "fced";
   cout << solve(S) << endl;
}