for (i = 8; i >= 0; i--)

{

????for (j = 0; j <= i; j++)

???????? if (arr[j]>arr[j + 1]

}?? 這段怎么理解？一共10個(gè)數(shù)。需要做9組循環(huán)比較 所以 i 取8 。每組循環(huán)里arr[j] 和arr[j+1] 做比較和交換。

我自己寫的是這個(gè)：

#include <stdio.h>
int main()
{
??? double arr[]={1.78, 1.77, 1.82, 1.79, 1.85, 1.75, 1.86, 1.77, 1.81, 1.80};
??? int i,j;
??? printf("\n************排隊(duì)前*************\n");
??? for(i=0;i<10;i++)
??? {
??????? if(i != 9)? ?
??????????? printf("%.2f, ", arr[i]);? //%.2f表示小數(shù)點(diǎn)后精確到兩位
??????? else
??????????? printf("%.2f", arr[i]);??? //%.2f表示小數(shù)點(diǎn)后精確到兩位
??? }
??? for(i=0; i<9; i++)
??? {
??????? for(j=i+1;j<10;j++)
??????? {
??????????? if(????? arr[i] > arr[j]????? )????? //當(dāng)前面的數(shù)比后面的數(shù)大時(shí)
??????????? {
??????????????? double temp;??? //定義臨時(shí)變量temp
??????????????? temp = arr[i];???? //將前面的數(shù)賦值給temp
??????????????? arr[i] = arr[j];????????????? //前后之?dāng)?shù)顛倒位置
??????????????? arr[j] = temp;????????????? //將較大的數(shù)放在后面?? ?
??????????? }??????????????? ?
??????? }?????????????? ?
??? }
??? printf("\n************排隊(duì)后*************\n");
??? for(i=0;i<10;i++)
??? {
??????? if(i != 9)? ?
??????????? printf("%.2f, ", arr[i]);? //%.2f表示小數(shù)點(diǎn)后精確到兩位??? ?
??????? else
??????????? printf("%.2f", arr[i]);??? //%.2f表示小數(shù)點(diǎn)后精確到兩位
??? }
??? return 0;?? ?
}