數組的旋轉是指將數組假設為圓形數組，每次旋轉時將數組的元素向左或向右旋轉一個索引，一端的元素可以採用另一端的值。遞增數組意味著每個元素將大於或等於其前一個元素，遞減數組意味著每個元素將小於或等於前一個元素。
在這個問題中，我們給定一個數組，我們可以向左或向右旋轉數組，我們必須找出在一定的旋轉（可能為零）之後是否可以使數組增加或減少。 p>
在這種方法中，我們將旋轉數組，並且對於每次旋轉，我們將檢查當前數組是增加還是減少。
在下面的範例中，我們檢查是否可以透過旋轉給定陣列來增加或減少它。以下是輸入和預期輸出。
輸入：arr = [3, 4, 5, 6, 1, 2]
預期輸出：是
輸入：arr = [ 5, 1, 6, 2, 5, 3 ]
預期輸出：否
// function to rotate the given array
function rotate(arr){
var l = 0;
var r = arr.length-1;
while(l < r){
arr[l] += arr[r];
arr[r] = arr[l]-arr[r];
arr[l] = arr[l]-arr[r];
l++;
}
return arr;
}
// function to check if the given array is increasing or not
function increasing(arr){
// getting the size of array
var len = arr.length
// traversing over the array
for(var i = 1; i < len; i++){
if(arr[i] < arr[i-1]){
return false;
}
}
return true;
}
// function to check if the given array is decreasing or not
function decreasing(arr){
// getting the size of array
var len = arr.length
// traversing over the array
for(var i = 1; i < len; i++){
if(arr[i] > arr[i-1]){
return false;
}
}
return true;
}
// function to check whether the given array can become
// increasing or decreasing after certain rotations
function check(arr){
var k = arr.length
while(k--){
if(increasing(arr) || decreasing(arr)){
return true;
}
arr = rotate(arr);
}
return false;
}
// defining the arr's
var arr1 = [3, 4, 5, 6, 1, 2]
var arr2 = [5, 1, 6, 2, 5, 3]
console.log("The given array is: ");
console.log(arr1)
if(check(arr1) == true){
console.log("Yes, after some rotations given array can be transformed into an increasing or decreasing array");
}
else{
console.log("No, after some rotations given array cannot be transformed into an increasing or decreasing array");
}
console.log("The given array is: ");
console.log(arr2)
if(check(arr2) == true){
console.log("Yes, after some rotations given array can be transformed into an increasing or decreasing array");
}
else{
console.log("No, after some rotations given array cannot be transformed into an increasing or decreasing array");
}
The given array is: [ 3, 4, 5, 6, 1, 2 ] Yes, after some rotations given array can be transformed into an increasing or decreasing array The given array is: [ 5, 1, 6, 2, 5, 3 ] No, after some rotations given array cannot be transformed into an increasing or decreasing array
上述程式碼的時間複雜度為O(N*N)，空間複雜度為O(1)。
在前面的陣列中，我們檢查了每次旋轉陣列是否增加或減少，在這種方法中，我們將部分檢查增加或減少的陣列。
// function to check if the given array is increasing or not
function increasing(arr){
// getting the size of array
var len = arr.length
// traversing over the array
var i = 0;
for(var i = 1; i < len; i++){
if(arr[i] < arr[i-1]){
break;
}
}
if(i == len) return true;
i++;
for(; i< len; i++){
if(arr[i] < arr[i-1]){
return false;
}
}
return arr[len-1] <= arr[0];
}
// function to check if the given array is decreasing or not
function decreasing(arr){
// getting the size of array
var len = arr.length
// traversing over the array
var i = 0;
for(var i = 1; i < len; i++){
if(arr[i] > arr[i-1]){
break;
}
}
if(i == len) return true;
i++;
for(; i< len; i++){
if(arr[i] > arr[i-1]){
return false;
}
}
return arr[len-1] >= arr[0];
}
// function to check whether the given array can become increasing or decreasing after certain rotations
function check(arr){
if(increasing(arr) || decreasing(arr)){
return true;
}
else{
return false;
}
}
// defining the arr's
var arr1 = [3, 4, 7, 6, 1, 2]
var arr2 = [5, 1, 6, 2, 5, 3]
console.log("The given array is: ");
console.log(arr1)
if(check(arr1) == true){
console.log("Yes, after some rotations given array can be transformed into an increasing or decreasing array");
}
else{
console.log("No, after some rotations given array cannot be transformed into an increasing or decreasing array");
}
console.log("The given array is: ");
console.log(arr2)
if(check(arr2) == true){
console.log("Yes, after some rotations given array can be transformed into an increasing or decreasing array");
}
else{
console.log("No, after some rotations given array cannot be transformed into an increasing or decreasing array");
}
The given array is: [ 3, 4, 7, 6, 1, 2 ] No, after some rotations given array cannot be transformed into an increasing or decreasing array The given array is: [ 5, 1, 6, 2, 5, 3 ] No, after some rotations given array cannot be transformed into an increasing or decreasing array
上述程式碼的時間複雜度為O(N)，空間複雜度為O(1)。
在本教程中，我們實作了一個 JavaScript 程序，用於檢查是否可以透過旋轉給定數組來增加或減少它。我們實作了兩種時間複雜度為 O(N*N) 和 O(N) 的方法，且空間複雜度均為 O(1)。
以上是JavaScript 程式檢查是否可以透過旋轉數組來增加或減少數組的詳細內容。更多資訊請關注PHP中文網其他相關文章！
