C++ code to find two substrings with one minimal substring

Suppose we have a lowercase string S with n characters. We have to find two non-empty substrings P and Q, such that −

• Both P and Q are subsequences of S

• For each index i, S[i] belong to exactly one of P and Q.

• P is lexicographically minimum as possible.

So, if the input is like S = "thelightsaber", then the output will be 10, because we need 2 red notebooks, 3 green notebooks, and 5 blue notebooks.

Steps

To solve this, we will follow these steps −

c := S sort the array c a := position of (c[0]) in S delete c from S print c[0] and S

Example

Let us see the following implementation to get better understanding −

#include <bits/stdc++.h> using namespace std; void solve(string S){    string c = S;    sort(c.begin(), c.end());    int a = S.find(c[0]);    S.erase(S.begin() + a);    cout << c[0] << ", " << S << endl; } int main(){    string S = "thelightsaber";    solve(S); }

Input

"thelightsaber"

Output

a, thelightsber