Chapter04

4.6

//零存整取问题， 每月同一天存入银行50元，单利计息，月利率为5%， 求一年后的本利和

#include<stdio.h>
#define M 50 //本金
#define R 0.005   //月利率
int main() {int i;float sum1 = 0, sum2 = 0;for ( i = 1; i <= 12 ; i++) //12个月一年{sum1 = sum1 + M;//本金和sum2 = sum2 + sum1 * R;// 利息和}printf("sum1 = %.2f  sum2 = %.2f  sum1 + sum2 = %.2f", sum1, sum2, sum1 + sum2);return 0;
}

4.8

//输入天数，输出周数和天数，例 如  输入：17， 输入 2 周 3 天#include<stdio.h>
int main() {int num;printf("请输入天数：");scanf_s("%d", &num);if (num % 7 != 0) {int week = num / 7;int day = num % 7;printf("天数%d 转换为 %d 周, %d天", num, week, day);}else {int multiple = num / 7;printf("天数%d 转化为 %d周, %d天", num, multiple, 0);}return 0;
}

4.9，4.10

#include<stdio.h>
#include<stdbool.h>
int ReverseInterger(int num);
int main() {int num;scanf_s("%d", &num);printf("翻转前的数字为：%d\n", num);int res = ReverseInterger(num);printf("翻转后的数字为：%d\n", res);return 0;
}/// <summary>
/// 翻转一个整数
/// </summary>
/// <param name="num"></param>
/// <returns></returns>
int ReverseInterger(int num) {int reversed = 0;bool is_negetive = false, if (num == 0) return 0;if (num < 0) {num = -num;is_negetive = true;}while (num != 0) {int remainder = num % 10;reversed = reversed * 10 + remainder;num /= 10;}if (is_negetive) {return -reversed;}else{return reversed;}}

4.11

#include<math.h>/// <summary>
/// 计算1—10的平方和
/// </summary>
/// <returns></returns>
int CalculateSquareSum() {int sum = 0;for (int i = 1; i <= 10; i++){sum += pow(i, 2);}return sum;
}