Given two numbers N and M. Construct maximal number by permuting (changing order) the digits of N, not exceeding M.
Note : It is allowed to leave N as it is.
Input : N = 123, M = 222
Output : 213
There are total 3! permutations possible for N = 123, But the only permutation that satisfies the given condition is 213. Similarly, In example 2, there are total 4! permutations possible for N = 3921, But the only permutation that satisfies the given condition is 9321.
Input : N = 3921, M = 10000
Output : 9321
Approach : Let’s construct the answer digit by digit starting from the leftmost. We are asked to build lexicographically maximal answer. So in this order, we should choose the greatest digit on each step. The approach is to iterate over all possible digits starting from the greatest. For each digit check if it’s possible to put it in this position and compare the resulting number with number M. If it comes less than or equal to the value of M, then proceed to the next digit.
Below is the CPP implementation:
- Permutation of an array that has smaller values from another array
- Number of palindromic permutations | Set 1
- Count the number of special permutations
- Find the number of good permutations
- Generate all cyclic permutations of a number
- Largest number smaller than or equal to N divisible by K
- Largest smaller number possible using only one swap operation
- Find the closest and smaller tidy number
- Find largest number smaller than N with same set of digits
- Number of Permutations such that no Three Terms forms Increasing Subsequence
- Number of permutations of a string in which all the occurrences of a given character occurs together
- Number of unique permutations starting with 1 of a Binary String
- Maximize the product of four factors of a Number
- Largest number smaller than or equal to n and digits in non-decreasing order
- Number of ways to remove elements to maximize arithmetic mean
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