C语言程序设计：现代设计方法习题笔记《chapter4》

第一题

示例代码：

#include<stdio.h>

int main()
{
	printf("Enter a two-digit number: ");
	int number,ten_n,g_n;
	scanf_s("%d", &number);
	ten_n = number / 10;
	g_n = number % 10;
	printf("The reversal is %d%d", g_n, ten_n);
	return 0;
}

 输出：

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第二题

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解题思路：这道题的解题思路有很多，一种思路就是分别求出每个位上的数字，然后排序输出，不难给出代码。 

示例代码：

#include<stdio.h>

int main()
{
	printf("Enter a two-digit number: ");
	int number, hund_n, ten_n, g_n;
	scanf_s("%d", &number);
	hund_n = number / 100;
	ten_n = (number-hund_n*100) / 10;
	g_n = (number-hund_n*100) % 10;
	//g_n = number-hund_n*100-ten_n*10;
	printf("The reversal is %d%d%d", g_n, ten_n, hund_n);
	return 0;
}

 输出

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第三题

解题思路：%1d代表一位整数，所以输入的数字是按照个数组合起来的，而不是眼睛看起来通常意义上的几百，如此可以解答。

示例代码： 

#include<stdio.h>

int main()
{
	printf("Enter a two-digit number: ");
	int  hund_n, ten_n, g_n;
	scanf_s("%1d", &hund_n);
	scanf_s("%1d", &ten_n);
	scanf_s("%1d", &g_n);
	
	//g_n = number-hund_n*100-ten_n*10;
	printf("The reversal is %d%d%d", g_n, ten_n, hund_n);
	return 0;
}

 输出

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第四题

解题思路：根据题中提示，需要用累除连续除4次8，然后将余数排列出来即可。

示例代码

#include<stdio.h>

int main()
{
	printf("Enter a number betweeen 0 and 32767: ");
	int number;
	scanf_s("%d", &number);
	int a, b, c, d, e;
	int temp_y, temp_r;
	temp_y = number % 8;
	a = temp_y;

	temp_r = number / 8;
	b = temp_r % 8;

	temp_r = temp_r / 8;
	c = temp_r % 8;

	temp_r = temp_r / 8;
	d = temp_r % 8;

	temp_r = temp_r / 8;
	e = temp_r % 8;
	printf("%d%d%d%d%d", e, d, c, b, a);
	return 0;
}

输出 

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第五题

 题目分析：这个题不难，关键在于审题，计算规则要看清楚，别搞错了。

示例代码

#include<stdio.h>
int main()
{
	int b, a1, a2, a3, a4, a5, b1, b2, b3, b4, b5;
	printf("Enter the first 11 digits of UPC: ");
	scanf_s("%1d%1d%1d%1d%1d%1d%1d%1d%1d%1d%1d",&b, &a1, &a2, &a3, &a4, &a5, &b1, &b2, &b3, &b4, &b5);
	int result;
	int first_sum,second_sum, total;
	first_sum = b + a2 + a4 + b1 + b3 + b5;
	second_sum = a1 + a3 + a5 + b2 + b4;
	total = 3 * first_sum + second_sum;
	result = 9 - (total - 1) % 10;
	printf("Check digit: %d", result);
	return 0;
}

输出

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第六题

题目分析：这种长臭的题，耐心看，提取出有用信息转换为代码语言。

示例代码

#include<stdio.h>
int main()
{
	int a1, a2, a3, a4, a5,a6, b1, b2, b3, b4, b5, b6;
	printf("Enter the first 11 digits of UPC: ");
	scanf_s("%1d%1d%1d%1d%1d%1d%1d%1d%1d%1d%1d%d", &a1, &a2, &a3, &a4, &a5,&a6, &b1, &b2, &b3, &b4, &b5,&b6);
	int result;
	int first_sum, second_sum, total;
	first_sum = a6 + a2 + a4 + b2 + b4 + b6;
	second_sum = a1 + a3 + a5 + b1 + b3+b5;
	total = 3 * first_sum + second_sum;
	result = 9 - (total - 1) % 10;
	printf("Check digit: %d", result);
	return 0;
}

输出

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