1. 打印Hello World
#include <stdio.h>
int main() {
printf("Hello World!\n");
return 0;
}
2. 输入输出整数
#include <stdio.h>
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
printf("You entered: %d\n", num);
return 0;
}
3. 计算两个数的和
#include <stdio.h>
int main() {
int a, b, sum;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
sum = a + b;
printf("Sum = %d\n", sum);
return 0;
}
4. 计算两个数的差
#include <stdio.h>
int main() {
int a, b, difference;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
difference = a - b;
printf("Difference = %d\n", difference);
return 0;
}
5. 计算两个数的乘积
#include <stdio.h>
int main() {
int a, b, product;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
product = a * b;
printf("Product = %d\n", product);
return 0;
}
6. 计算两个数的商
#include <stdio.h>
int main() {
int a, b, quotient;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
if (b != 0) {
quotient = a / b;
printf("Quotient = %d\n", quotient);
} else {
printf("Division by zero is not allowed.\n");
}
return 0;
}
7. 计算两个数的余数
#include <stdio.h>
int main() {
int a, b, remainder;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
remainder = a % b;
printf("Remainder = %d\n", remainder);
return 0;
}
8. 判断一个数是否为偶数
#include <stdio.h>
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (num % 2 == 0) {
printf("%d is even.\n", num);
} else {
printf("%d is odd.\n", num);
}
return 0;
}
9. 判断一个数是否为奇数
#include <stdio.h>
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (num % 2 != 0) {
printf("%d is odd.\n", num);
} else {
printf("%d is even.\n", num);
}
return 0;
}
10. 计算一个数的平方
#include <stdio.h>
int main() {
int num, square;
printf("Enter an integer: ");
scanf("%d", &num);
square = num * num;
printf("Square = %d\n", square);
return 0;
}
11. 计算一个数的立方
#include <stdio.h>
int main() {
int num, cube;
printf("Enter an integer: ");
scanf("%d", &num);
cube = num * num * num;
printf("Cube = %d\n", cube);
return 0;
}
12. 计算一个数的阶乘
#include <stdio.h>
int main() {
int num, factorial = 1;
printf("Enter an integer: ");
scanf("%d", &num);
if (num < 0) {
printf("Factorial of a negative number is not defined.\n");
} else {
for (int i = 1; i <= num; i++) {
factorial *= i;
}
printf("Factorial = %d\n", factorial);
}
return 0;
}
13. 计算两个数的最大公约数
#include <stdio.h>
int gcd(int a, int b) {
if (b == 0) {
return a;
} else {
return gcd(b, a % b);
}
}
int main() {
int a, b;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
printf("GCD = %d\n", gcd(a, b));
return 0;
}
14. 计算两个数的最小公倍数
#include <stdio.h>
int main() {
int a, b, lcm;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
lcm = (a * b) / gcd(a, b);
printf("LCM = %d\n", lcm);
return 0;
}
15. 判断一个数是否为素数
#include <stdio.h>
int main() {
int num, i, is_prime = 1;
printf("Enter an integer: ");
scanf("%d", &num);
if (num <= 1) {
is_prime = 0;
} else {
for (i = 2; i <= num / 2; i++) {
if (num % i == 0) {
is_prime = 0;
break;
}
}
}
if (is_prime) {
printf("%d is a prime number.\n", num);
} else {
printf("%d is not a prime number.\n", num);
}
return 0;
}
16. 计算一个数的平方根
#include <stdio.h>
#include <math.h>
int main() {
double num, sqrt_num;
printf("Enter an integer: ");
scanf("%lf", &num);
sqrt_num = sqrt(num);
printf("Square root = %f\n", sqrt_num);
return 0;
}
17. 计算一个数的立方根
#include <stdio.h>
#include <math.h>
int main() {
double num, cbrt_num;
printf("Enter an integer: ");
scanf("%lf", &num);
cbrt_num = cbrt(num);
printf("Cube root = %f\n", cbrt_num);
return 0;
}
18. 计算一个数的阶乘（递归）
#include <stdio.h>
int factorial(int n) {
if (n <= 1) {
return 1;
} else {
return n * factorial(n - 1);
}
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
printf("Factorial = %d\n", factorial(num));
return 0;
}
19. 计算一个数的阶乘（循环）
#include <stdio.h>
int main() {
int num, factorial = 1;
printf("Enter an integer: ");
scanf("%d", &num);
for (int i = 1; i <= num; i++) {
factorial *= i;
}
printf("Factorial = %d\n", factorial);
return 0;
}
20. 判断一个数是否为完全数
#include <stdio.h>
int main() {
int num, sum = 0, i;
printf("Enter an integer: ");
scanf("%d", &num);
for (i = 1; i <= num / 2; i++) {
if (num % i == 0) {
sum += i;
}
}
if (sum == num) {
printf("%d is a perfect number.\n", num);
} else {
printf("%d is not a perfect number.\n", num);
}
return 0;
}
21. 计算一个数的位数
#include <stdio.h>
int main() {
int num, count = 0;
printf("Enter an integer: ");
scanf("%d", &num);
while (num != 0) {
num /= 10;
count++;
}
printf("Number of digits = %d\n", count);
return 0;
}
22. 判断一个数是否为回文数
#include <stdio.h>
int main() {
int num, original_num, reversed_num = 0, remainder;
printf("Enter an integer: ");
scanf("%d", &num);
original_num = num;
while (num != 0) {
remainder = num % 10;
reversed_num = reversed_num * 10 + remainder;
num /= 10;
}
if (original_num == reversed_num) {
printf("%d is a palindrome.\n", original_num);
} else {
printf("%d is not a palindrome.\n", original_num);
}
return 0;
}
23. 计算一个数的幂
#include <stdio.h>
int power(int base, int exponent) {
int result = 1;
while (exponent != 0) {
result *= base;
--exponent;
}
return result;
}
int main() {
int base, exponent;
printf("Enter base and exponent: ");
scanf("%d %d", &base, &exponent);
printf("%d to the power of %d is %d\n", base, exponent, power(base, exponent));
return 0;
}
24. 计算一个数的阶乘（函数）
#include <stdio.h>
int factorial(int n) {
if (n <= 1) {
return 1;
} else {
return n * factorial(n - 1);
}
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
printf("Factorial = %d\n", factorial(num));
return 0;
}
25. 计算两个数的最大公约数（函数）
#include <stdio.h>
int gcd(int a, int b) {
if (b == 0) {
return a;
} else {
return gcd(b, a % b);
}
}
int main() {
int a, b;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
printf("GCD = %d\n", gcd(a, b));
return 0;
}
26. 计算两个数的最小公倍数（函数）
#include <stdio.h>
int lcm(int a, int b) {
return (a * b) / gcd(a, b);
}
int main() {
int a, b;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
printf("LCM = %d\n", lcm(a, b));
return 0;
}
27. 判断一个数是否为素数（函数）
#include <stdio.h>
int is_prime(int n) {
if (n <= 1) {
return 0;
}
for (int i = 2; i <= n / 2; i++) {
if (n % i == 0) {
return 0;
}
}
return 1;
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (is_prime(num)) {
printf("%d is a prime number.\n", num);
} else {
printf("%d is not a prime number.\n", num);
}
return 0;
}
28. 计算一个数的平方根（函数）
#include <stdio.h>
#include <math.h>
double square_root(double num) {
return sqrt(num);
}
int main() {
double num;
printf("Enter an integer: ");
scanf("%lf", &num);
printf("Square root = %f\n", square_root(num));
return 0;
}
29. 计算一个数的立方根（函数）
#include <stdio.h>
#include <math.h>
double cube_root(double num) {
return cbrt(num);
}
int main() {
double num;
printf("Enter an integer: ");
scanf("%lf", &num);
printf("Cube root = %f\n", cube_root(num));
return 0;
}
30. 计算一个数的阶乘（递归函数）
#include <stdio.h>
int factorial(int n) {
if (n <= 1) {
return 1;
} else {
return n * factorial(n - 1);
}
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
printf("Factorial = %d\n", factorial(num));
return 0;
}
31. 计算一个数的阶乘（循环函数）
#include <stdio.h>
int factorial(int n) {
int result = 1;
for (int i = 1; i <= n; i++) {
result *= i;
}
return result;
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
printf("Factorial = %d\n", factorial(num));
return 0;
}
32. 判断一个数是否为完全数（函数）
#include <stdio.h>
int is_perfect_number(int n) {
int sum = 0, i;
for (i = 1; i <= n / 2; i++) {
if (n % i == 0) {
sum += i;
}
}
return sum == n;
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (is_perfect_number(num)) {
printf("%d is a perfect number.\n", num);
} else {
printf("%d is not a perfect number.\n", num);
}
return 0;
}
33. 计算一个数的位数（函数）
#include <stdio.h>
int number_of_digits(int n) {
int count = 0;
while (n != 0) {
n /= 10;
count++;
}
return count;
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
printf("Number of digits = %d\n", number_of_digits(num));
return 0;
}
34. 判断一个数是否为回文数（函数）
#include <stdio.h>
int is_palindrome(int n) {
int original_n = n, reversed_n = 0, remainder;
while (n != 0) {
remainder = n % 10;
reversed_n = reversed_n * 10 + remainder;
n /= 10;
}
return original_n == reversed_n;
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (is_palindrome(num)) {
printf("%d is a palindrome.\n", num);
} else {
printf("%d is not a palindrome.\n", num);
}
return 0;
}
35. 计算一个数的幂（函数）
#include <stdio.h>
int power(int base, int exponent) {
int result = 1;
while (exponent != 0) {
result *= base;
--exponent;
}
return result;
}
int main() {
int base, exponent;
printf("Enter base and exponent: ");
scanf("%d %d", &base, &exponent);
printf("%d to the power of %d is %d\n", base, exponent, power(base, exponent));
return 0;
}
36. 计算两个数的最大公约数（递归函数）
#include <stdio.h>
int gcd(int a, int b) {
if (b == 0) {
return a;
} else {
return gcd(b, a % b);
}
}
int main() {
int a, b;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
printf("GCD = %d\n", gcd(a, b));
return 0;
}
37. 计算两个数的最小公倍数（递归函数）
#include <stdio.h>
int lcm(int a, int b) {
return (a * b) / gcd(a, b);
}
int main() {
int a, b;
printf("Enter two integers: ");
scanf("%d %d", &a, &b);
printf("LCM = %d\n", lcm(a, b));
return 0;
}
38. 判断一个数是否为素数（递归函数）
#include <stdio.h>
int is_prime(int n) {
if (n <= 1) {
return 0;
}
if (n == 2) {
return 1;
}
if (n % 2 == 0) {
return 0;
}
return is_prime(n - 2);
}
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (is_prime(num)) {
printf("%d is a prime number.\n", num);
} else {
printf("%d is not a prime number.\n", num);
}
return 0;
}
39. 计算一个数的平方根（递归函数）
”`c
#include
double square_root(double num) {
if (num == 0 || num