可汗學院 - 挑戰：實現插入排序

Question

我正在參加一個算法類可汗學院的JavaScript。我寫了這樣的代碼：

var insert = function(array, rightIndex, value) { 
    for(var i = rightIndex; 
     i > 0 && array[i-1] > value; 
     i--) { 
     array[i] = array[i-1]; 
    } 
    array[i] = value; 
}; 

var insertionSort = function(array) { 
for (var st = 1; st < array.length; st++) { 
    insert(array, st, array[st]); 
} 
}; 

var array = [22, 11, 99, 88, 9, 7, 42]; 
insertionSort(array); 
println("Array after sorting: " + array); 
Program.assertEqual(array, [7, 9, 11, 22, 42, 88, 99]); 

現在我想知道這裏有什麼問題，我不能進入下一級...請幫助。 :)

Answer 1

您的程序是正確的，但可能是語法錯誤： 使用Console.log（「Array after sorting：」+ array）; 而不是： println（「排序後的數組：」+數組）; in java腳本沒有任何方法println輸出。

Answer 2

var insertionSort = function (unsortedList) { 
    var len = unsortedList.length; 

    for(var i = 0; i < len; i++) { 
    var tmp = unsortedList[i]; //Copy of the current element. 
    /*Check through the sorted part and compare with the 
    number in tmp. If large, shift the number*/ 
    for(var j = i - 1; j >= 0 && (unsortedList[j] > tmp); j--) { 
     //Shift the number 
     unsortedList[j+1] = unsortedList[j]; 
    } 
    //Insert the copied number at the correct position 
    //in sorted part. 
    unsortedList[j+1] = tmp; 
    } 
}; 
var array = [22, 11, 99, 88, 9, 7, 42]; 
insertionSort(array); 
println("Array after sorting: " + array); 

Answer 3

to all :)這是正確的解決方案。您無法更改已經寫入的內容。

var insert = function(array, rightIndex, value) { 
for(var j = rightIndex; 
     j >= 0 && array[j] > value; 
     j--) { 
     array[j + 1] = array[j]; 
    } 
    array[j + 1] = value; 
}; 
var insertionSort = function(array) { 
for (var st = 1; st < array.length; st++) { 
    insert(array, st - 1, array[st]); 
} 
}; 
var array = [22, 11, 99, 88, 9, 7, 42]; 
insertionSort(array); 
println("Array after sorting: " + array); 
Program.assertEqual(array, [7, 9, 11, 22, 42, 88, 99]); 

Answer 4

這個工程...

var insert = function(array, rightIndex, value) { 
    for (var i = rightIndex; i>=0 && array[i] > value; i --) { 
     array[i+1] = array[i]; 
     } 
    array[i+1] = value; 
};