c++用数组做冒泡算法的一个问题

Question

代码运行达不到排序的效果
但是把数组长度换成11，然后只用a[1]到a[10]十个数，就好了，请问为什么？

#include<iostream>
using namespace std;
int main()
{
    int a[10],i,j,k;
    cout<<"please inter numbers:"<<endl;
    for(**i=0;i<10;i++)
        cin>>a[i];
    cout<<endl;
    for(j=1;j<10;j++)
        for(i=1;i<=10-j;i++)
            if(a[i]>a[i+1])
            {k=a[i];a[i]=a[i+1];a[i+1]=k;}
            cout<<"the sorted number is:"<<endl;
            for(**i=0;i<10;i++)
                cout<<a[i]<<" ";
            cout<<endl;
            return 0;
}

Answer 1

因为你算的是从1开始比较，而正常应该是从零开始比较：

#include<iostream>
using namespace std;
int main()
{
    int a[10], i, j, k;
    cout << "please inter numbers:" << endl;
    for (i = 0; i < 10; i++)
        cin >> a[i];
    cout << endl;
    for (i = 0; i < 10 - 1; i++)
    {
        for (j = 0; j<10 - 1 - i; j++){
            if (a[j] > a[j + 1])
            {
                k = a[j];
                a[j] = a[j + 1];
                a[j + 1] = k;
            }
        }
    }
    cout << "the sorted number is:" << endl;
    for (i = 0; i < 10; i++)
        cout << a[i] << " ";
    cout << endl;
    return 0;
}