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#1375 - Number of Times Binary String Is Prefix-Aligned
Problem Description
You have a 1-indexed binary string of length n where all the bits are 0 initially. We will flip all the bits of this binary string (i.e., change them from 0 to 1) one by one. You are given a 1-indexed integer array flips where flips[i] indicates that the bit at index i will be flipped in the ith step.
A binary string is prefix-aligned if, after the ith step, all the bits in the inclusive range [1, i] are ones and all the other bits are zeros.
Return the number of times the binary string is prefix-aligned during the flipping process.
Solution
/**
* @param {number[]} light
* @return {number}
*/
var numTimesAllBlue = function(flips) {
let maxFlipped = 0;
let result = 0;
flips.forEach((position, step) => {
maxFlipped = Math.max(maxFlipped, position);
if (maxFlipped === step + 1) result++;
});
return result;
};