We will generate all permutations of the given string in lexicographic order.
Start by sorting the string in increasing order.
Generate the next higher permutation until all permutations are exhausted.
As we generate each permutation, compare it with the given string.
If a match is found, output the current rank (the number of permutations generated so far including the matching one).
If no match is found, increment the rank counter (ans) by 1 until the match is found.
Return the rank once the matching string is found.

Code

#include <bits/stdc++.h>
using namespace std;

// Comparison function for qsort
int compare(const void* a, const void* b) {
    // Compare two characters and return their difference
    return (*(char*)a - *(char*)b);
}

// Finds the smallest character which is greater than 'first' in str[l...h]
int findCeil(char str[], char first, int l, int h) {
    // Store index of ceiling character
    int ceilIndex = l;
    // Iterate over the range to find smallest char greater than 'first'
    for (int i = l + 1; i <= h; i++) {
        if (str[i] > first && str[i] < str[ceilIndex]) {
            ceilIndex = i;
        }
    }
    // Return the index found
    return ceilIndex;
}

// Generates sorted permutations and stores them in vector 'v'
void sortedPermutations(char str[], vector<string>& v) {
    // Get the size of the string
    int size = strlen(str);
    // Sort the array in increasing order
    qsort(str, size, sizeof(str[0]), compare);
    // Boolean flag to indicate if all permutations are printed
    bool isFinished = false;
    // Loop un