我正确追踪这个吗?

时间:2012-04-02 00:50:06

标签: arrays algorithm sorting

我的计算机科学老师为我们分配了不同的排序算法。我想确保我的追踪是正确的 选择排序:

void selection sort
{
  for(int i = 0; i < ray.length-1;i++)
  {
    int min = i
    for(int j = i +1; j<ray.length;j++;)
    {
      if(ray[j] < ray[min])
        min = j;
    }
    if(min != i)
    {
      int temp = ray[min]
      ray[min] = ray[i]
      ray[i] = temp;
    }
  }
}

原始数组= {4,2,6,3,5,1} 排序顺序:

1st pass - 2,4,6,3,5,1
2nd pass - 2,3,6,4,5,1
3rd pass - 2,3,4,6,5,1
4th pass - 2,3,4,5,6,1
5th pass - 2,3,4,5,1,6
6th pass - 2,3,4,1,5,6
7th pass - 2,3,1,4,5,6
8th pass - 2,1,3,4,5,6
9th pass - 1,2,3,4,5,6

1 个答案:

答案 0 :(得分:0)

您的痕迹似乎不正确

当你开始时你有阵列

{4,2,6,3,5,1}

在外循环期间

min = i // i = 0 min = 0

在内循环中你做这个

if(ray[j] < ray[min]) //2 < 4 TRUE (j = 1 min = 0)
   min = j;
//loop increment j
if(ray[j] < ray[min]) //6 < 2 FALSE (j = 2 min = 1)
//loop increment j
if(ray[j] < ray[min]) //3 < 2 FALSE (j = 3 min = 1)
//loop increment j
if(ray[j] < ray[min]) //5 < 2 FALSE (j = 4 min = 1)
//loop increment j
if(ray[j] < ray[min]) // 1 < 2 TRUE (j = 5 min = 1)
   min = j;
//loop increment j (j = 6 end loop)

if(min != i) //min = 5 i = 0 TRUE
   temp = ray[min] //temp = 1
   ray[min] ray[i] //ray[5] = ray[0] ray[5] = 4
   ray[i] = temp //ray[0] = 1

//loop increment i to 1 continue through this

此时的数组

{1,2,6,3,5,4}

你应该可以继续使用外循环的其余部分