MountainArray
HTML
find peak index in mountain array solve in O(log(n))
sorted ==> binarySearch
1 2 3 4 3 2 ==> 4
0, 3 ,5,7,4 ,2 ==> 7
JavaScript
function mountain(a) {
let s = 0,
e = a.length,
mid = 0;
while (s < e) {
mid = Math.floor((s + e) / 2);
if (a[mid] < a[mid + 1]) {
s = mid + 1;
} else {
e = mid;
}
}
return s; //return start this s different
}
console.log(mountain([1,2,4,6,4,2]))