两个变量之间值互换 

 1 //实现两变量的值进行互换
 2 short num_v1 = 20;
 3 short num_v2 = 40;
 4 
 5 void change_middle()
 6 {
 7     //借助中间变量
 8     short temp;
 9 
10     temp = num_v1;
11 
12     num_v1 = num_v2;
13 
14     num_v2 = temp;
15 }
16 void change_2()
17 {
18     //不借助中间变量
19     num_v1 = num_v1 + num_v2;//v1=20,v2=40->20+40->v1=60,v2=40
20     num_v2 = num_v1 - num_v2;//v1=60,v2=40->60-40->v1=60,v2=20
21     num_v1 = num_v1 - num_v2;//v1=60,v2=20->60-20->v1=40,v2=20
22 }
23 void change_3()
24 {
25     //不借助中间变量
26     num_v1 = num_v1 * num_v2;//v1=20,v2=40->20*40->v1=80,v2=40
27     num_v2 = num_v1 / num_v2;//v1=80,v2=40->80/40->v1=80,v2=20
28     num_v1 = num_v1 / num_v2;//v1=80,v2=20->80/20->v1=40,v2=20
29     
30 }
31 void main()
32 {
33     
34     printf("before:num_v1=%d,num_v2=%d", num_v1, num_v2);
35 
36     //change_middle();
37     //change_2();
38     change_3();
39     putchar('\n');
40     printf("after:num_v1=%d,num_v2=%d", num_v1, num_v2);
41 
42     getchar();
43 
44 
45 }

 

posted on 2017-12-13 12:39  潜龙传  阅读(270)  评论(0)    收藏  举报

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