caub/count-nonrepetitive-numbers.js

## count-nonrepetitive-numbers.js
// 2 globals defined at boot of nodejs engine
rl = cb => require('readline').createInterface({input:process.stdin}).on('line',cb);
print = console.log;

/*
Let's call an integer "repetitive" if it contains two of the same digit in a row. For example, 12232 is repetitive but 1232 is not.
Given a positive integer n < 10^15, return the number of nonrepetitive integers in [1..n].
*/
// prog
rl(s=>{r=0;d=s.length-1;for(i=0;i<=d;i++){r+=(i>0&&s[i-1]<s[i]?s[i]-1:s[i])*9**(d-i);if(s[i-1]==s[i]){r--;break}}for(i=0;i<d;i++)r+=9**i;print(r)})
	// 2 globals defined at boot of nodejs engine
	rl = cb => require('readline').createInterface({input:process.stdin}).on('line',cb);
	print = console.log;

	/*
	Let's call an integer "repetitive" if it contains two of the same digit in a row. For example, 12232 is repetitive but 1232 is not.
	Given a positive integer n < 10^15, return the number of nonrepetitive integers in [1..n].
	*/
	// prog
	rl(s=>{r=0;d=s.length-1;for(i=0;i<=d;i++){r+=(i>0&&s[i-1]<s[i]?s[i]-1:s[i])9(d-i);if(s[i-1]==s[i]){r--;break}}for(i=0;i<d;i++)r+=9*i;print(r)})