increaseNumberRoundness.js

// Define an integer's roundness as the number of trailing zeroes in it.

// Given an integer n, check if it's possible to increase n's roundness by swapping some pair of its digits.

// Example

// For n = 902200100, the output should be
// increaseNumberRoundness(n) = true.

// One of the possible ways to increase roundness of n is to swap digit 1 with digit 0 preceding it: roundness of 902201000 is 3, and roundness of n is 2.

// For instance, one may swap the leftmost 0 with 1.

// For n = 11000, the output should be
// increaseNumberRoundness(n) = false.

// Roundness of n is 3, and there is no way to increase it.

function increaseNumberRoundness(n) {
var s = String(n).split(''), nonzero = 0;
for(var i = s.length-1; i >= 0; i--){
    if(nonzero < 1) {
        if(s[i] != "0") nonzero++;
  
    }else if(nonzero == 1) {
        if(s[i] == "0") return true;
    }
}
return false; 
}