function
isIncRotated(arr, n, minIndex, maxIndex) {
if
(arr[0] < arr[n - 1]) {
return
false
;
}
return
isIncreasing(arr, 0, maxIndex) && isIncreasing(arr, minIndex, n - 1);
}
function
isDecRotated(arr, n, minIndex, maxIndex) {
if
(arr[0] > arr[n - 1]) {
return
false
;
}
return
isDecreasing(arr, 0, minIndex) && isDecreasing(arr, maxIndex, n - 1);
}
function
isIncreasing(arr, l, r) {
for
(let i = l + 1; i <= r; i++) {
if
(arr[i - 1] > arr[i]) {
return
false
;
}
}
return
true
;
}
function
isDecreasing(arr, l, r) {
for
(let i = l + 1; i <= r; i++) {
if
(arr[i - 1] < arr[i]) {
return
false
;
}
}
return
true
;
}
function
checkIfSortRotated(arr) {
let minEle = Infinity;
let maxEle = -Infinity;
let minIndex = 0;
let maxIndex = 0;
for
(let i = 0; i < arr.length; i++) {
if
(arr[i] < arr[minIndex]) {
minIndex = i;
}
if
(arr[i] > arr[maxIndex]) {
maxIndex = i;
}
}
let res =
false
;
if
(maxIndex === minIndex - 1) {
res = isIncRotated(arr, arr.length, minIndex, maxIndex);
}
if
(minIndex === maxIndex - 1) {
res = isDecRotated(arr, arr.length, minIndex, maxIndex);
}
if
(res) {
console.log(
"YES"
);
}
else
{
console.log(
"NO"
);
}
}
let arr = [3, 4, 5, 1, 2];
checkIfSortRotated(arr);