C学习笔记——冒泡排序

冒泡排序

#include<stdio.h>
int main(void)
{
  int array[10] = {9,8,7,6,5,4,3,2,1,0};  //待排序的数组
  int i,j;
  int temp;
  for(i = 1; i < 10; i++)                 // i代表排序的次数，数组中包含10个数据，需要从第1位排到10位
  {
      for(j = i; j > 0; j--)             // 每一位需要与前面所有的位比较
      {
          if(array[j] < array[j-1])      // 如果比前面的值小，则换位
          {
                temp = array[j-1];
                array[j-1] = array[j];
                array[j] = temp;
          }
      }
  }
  for(i = 0; i < 10; i++)
  {
      printf("%d ", array[i]);
  }
}

• 抄袭国外的例子，好好消化一下

#include <stdio.h>
#include <stdbool.h>

#define MAX 10

int list[MAX] = {1,8,4,6,0,3,5,2,7,9};

void display() {
   int i;
   printf("[");

   // navigate through all items 
   for(i = 0; i < MAX; i++) {
      printf("%d ",list[i]);
   }

   printf("]\n");
}

void bubbleSort() {
   int temp;
   int i,j;

   bool swapped = false;

   // loop through all numbers 
   for(i = 0; i < MAX-1; i++) { 
      swapped = false;

      // loop through numbers falling ahead 
      for(j = 0; j < MAX-1-i; j++) {
         printf("     Items compared: [ %d, %d ] ", list[j],list[j+1]);

         // check if next number is lesser than current no
         //   swap the numbers. 
         //  (Bubble up the highest number)

         if(list[j] > list[j+1]) {
            temp = list[j];
            list[j] = list[j+1];
            list[j+1] = temp;

            swapped = true;
            printf(" => swapped [%d, %d]\n",list[j],list[j+1]);
         }else {
            printf(" => not swapped\n");
         }

      }

      // if no number was swapped that means 
      //   array is sorted now, break the loop. 
      if(!swapped) {
         break;
      }

      printf("Iteration %d#: ",(i+1)); 
      display();
   }

}

main() {
   printf("Input Array: ");
   display();
   printf("\n");

   bubbleSort();
   printf("\nOutput Array: ");
   display();
}

输出结果
Input Array: [1 8 4 6 0 3 5 2 7 9 ]

     Items compared: [ 1, 8 ]  => not swapped
     Items compared: [ 8, 4 ]  => swapped [4, 8]
     Items compared: [ 8, 6 ]  => swapped [6, 8]
     Items compared: [ 8, 0 ]  => swapped [0, 8]
     Items compared: [ 8, 3 ]  => swapped [3, 8]
     Items compared: [ 8, 5 ]  => swapped [5, 8]
     Items compared: [ 8, 2 ]  => swapped [2, 8]
     Items compared: [ 8, 7 ]  => swapped [7, 8]
     Items compared: [ 8, 9 ]  => not swapped
Iteration 1#: [1 4 6 0 3 5 2 7 8 9 ]
     Items compared: [ 1, 4 ]  => not swapped
     Items compared: [ 4, 6 ]  => not swapped
     Items compared: [ 6, 0 ]  => swapped [0, 6]
     Items compared: [ 6, 3 ]  => swapped [3, 6]
     Items compared: [ 6, 5 ]  => swapped [5, 6]
     Items compared: [ 6, 2 ]  => swapped [2, 6]
     Items compared: [ 6, 7 ]  => not swapped
     Items compared: [ 7, 8 ]  => not swapped
Iteration 2#: [1 4 0 3 5 2 6 7 8 9 ]
     Items compared: [ 1, 4 ]  => not swapped
     Items compared: [ 4, 0 ]  => swapped [0, 4]
     Items compared: [ 4, 3 ]  => swapped [3, 4]
     Items compared: [ 4, 5 ]  => not swapped
     Items compared: [ 5, 2 ]  => swapped [2, 5]
     Items compared: [ 5, 6 ]  => not swapped
     Items compared: [ 6, 7 ]  => not swapped
Iteration 3#: [1 0 3 4 2 5 6 7 8 9 ]
     Items compared: [ 1, 0 ]  => swapped [0, 1]
     Items compared: [ 1, 3 ]  => not swapped
     Items compared: [ 3, 4 ]  => not swapped
     Items compared: [ 4, 2 ]  => swapped [2, 4]
     Items compared: [ 4, 5 ]  => not swapped
     Items compared: [ 5, 6 ]  => not swapped
Iteration 4#: [0 1 3 2 4 5 6 7 8 9 ]
     Items compared: [ 0, 1 ]  => not swapped
     Items compared: [ 1, 3 ]  => not swapped
     Items compared: [ 3, 2 ]  => swapped [2, 3]
     Items compared: [ 3, 4 ]  => not swapped
     Items compared: [ 4, 5 ]  => not swapped
Iteration 5#: [0 1 2 3 4 5 6 7 8 9 ]
     Items compared: [ 0, 1 ]  => not swapped
     Items compared: [ 1, 2 ]  => not swapped
     Items compared: [ 2, 3 ]  => not swapped
     Items compared: [ 3, 4 ]  => not swapped

Output Array: [0 1 2 3 4 5 6 7 8 9 ]