*结构-05. 有理数均值

 1 /*
 2  * Main.c
 3  * F5-结构-05. 有理数均值
 4  *  Created on: 2014年8月26日
 5  *      Author: Boomkeeper
 6  *********部分通过*浮点错误******
 7  */
 8
 9 #include <stdio.h>
10 /**
11  * 有理数结构体
12  */
13 struct rational {
14     int numerator;
15     int denominator;
16 };
17 /**
18  * 最大公约数
19  */
20 int greatCommonDivisor(int m, int n) {
21     int i;
22     for (i = (m < n ? m : n); i > 1; i--) {
23         if (m % i == 0 && n % i == 0)
24             break;
25     }
26     return i;
27 }
28
29 int main(void) {
30
31     int n; //题目中的N
32     struct rational num[101];
33     struct rational result;
34     int i;
35
36     scanf("%d", &n);
37     getchar();
38
39     for (i = 0; i < n; i++) {
40         scanf("%d/%d", &num[i].numerator, &num[i].denominator);
41     }
42
43     result.numerator = num[0].numerator;
44     result.denominator = num[0].denominator;
45
46     //通分求和
47     for (i = 1; i < n; i++) {
48         result.numerator = result.numerator * num[i].denominator
49                 + num[i].numerator * result.denominator;
50         result.denominator = result.denominator * num[i].denominator;
51         if (result.numerator != 0) {
52             //避免累加和超出int范围，每次累加后进行约分
53             int gcd = greatCommonDivisor(result.numerator, result.denominator);
54             result.numerator /= gcd;
55             result.denominator /= gcd;
56         }
57
58     }
59
60     //求平均
61     result.denominator *= n;
62     int gcd = greatCommonDivisor(result.numerator, result.denominator);
63     result.numerator /= gcd;
64     result.denominator /= gcd;
65
66     //输出结果
67     if (result.denominator == 1)
68         printf("%d\n", result.numerator);
69     else
70         printf("%d/%d\n", result.numerator, result.denominator);
71
72     return 0;
73 }

题目链接：

http://pat.zju.edu.cn/contests/basic-programming/%E7%BB%93%E6%9E%84-05