1. 打印“Hello, World!”
#include <stdio.h>
int main() {
printf("Hello, World!\n");
return 0;
}
2. 输入两个整数,计算并输出它们的和
#include <stdio.h>
int main() {
int num1, num2, sum;
printf("Enter two integers: ");
scanf("%d %d", &num1, &num2);
sum = num1 + num2;
printf("Sum = %d\n", sum);
return 0;
}
3. 输入一个整数,判断它是正数、负数还是零
#include <stdio.h>
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (num > 0) {
printf("Positive\n");
} else if (num < 0) {
printf("Negative\n");
} else {
printf("Zero\n");
}
return 0;
}
4. 输入三个整数,找出最大值
#include <stdio.h>
int main() {
int num1, num2, num3, max;
printf("Enter three integers: ");
scanf("%d %d %d", &num1, &num2, &num3);
max = num1;
if (num2 > max) {
max = num2;
}
if (num3 > max) {
max = num3;
}
printf("Maximum = %d\n", max);
return 0;
}
5. 输入一个圆的半径,计算并输出其面积和周长
#include <stdio.h>
#define PI 3.14159
int main() {
float radius, area, circumference;
printf("Enter the radius of the circle: ");
scanf("%f", &radius);
area = PI * radius * radius;
circumference = 2 * PI * radius;
printf("Area = %.2f\n", area);
printf("Circumference = %.2f\n", circumference);
return 0;
}
6. 输入一个整数,判断它是奇数还是偶数
#include <stdio.h>
int main() {
int num;
printf("Enter an integer: ");
scanf("%d", &num);
if (num % 2 == 0) {
printf("Even\n");
} else {
printf("Odd\n");
}
return 0;
}
7. 输入三个整数,对它们进行排序
#include <stdio.h>
int main() {
int num1, num2, num3, temp;
printf("Enter three integers: ");
scanf("%d %d %d", &num1, &num2, &num3);
if (num1 > num2) {
temp = num1;
num1 = num2;
num2 = temp;
}
if (num2 > num3) {
temp = num2;
num2 = num3;
num3 = temp;
}
if (num1 > num2) {
temp = num1;
num1 = num2;
num2 = temp;
}
printf("Sorted numbers: %d %d %d\n", num1, num2, num3);
return 0;
}
8. 输入一个字符串,将其转换为小写
#include <stdio.h>
void toLowerCase(char *str) {
while (*str) {
if (*str >= 'A' && *str <= 'Z') {
*str += 'a' - 'A';
}
str++;
}
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
toLowerCase(str);
printf("Lowercase string: %s\n", str);
return 0;
}
9. 输入一个字符串,计算其中字符的数量
#include <stdio.h>
int countCharacters(char *str) {
int count = 0;
while (*str) {
count++;
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int length = countCharacters(str);
printf("Number of characters: %d\n", length);
return 0;
}
10. 输入一个字符串,将其逆序输出
#include <stdio.h>
void reverseString(char *str) {
int length = 0;
char *end = str;
while (*end) {
length++;
end++;
}
for (int i = length - 1; i >= 0; i--) {
printf("%c", str[i]);
}
printf("\n");
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
reverseString(str);
return 0;
}
11. 输入一个字符串,计算其中字母的数量
#include <stdio.h>
int countLetters(char *str) {
int count = 0;
while (*str) {
if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z')) {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int letters = countLetters(str);
printf("Number of letters: %d\n", letters);
return 0;
}
12. 输入一个字符串,计算其中数字的数量
#include <stdio.h>
int countDigits(char *str) {
int count = 0;
while (*str) {
if (*str >= '0' && *str <= '9') {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int digits = countDigits(str);
printf("Number of digits: %d\n", digits);
return 0;
}
13. 输入一个字符串,计算其中空格的数量
#include <stdio.h>
int countSpaces(char *str) {
int count = 0;
while (*str) {
if (*str == ' ') {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int spaces = countSpaces(str);
printf("Number of spaces: %d\n", spaces);
return 0;
}
14. 输入一个字符串,计算其中非字母字符的数量
#include <stdio.h>
int countNonLetters(char *str) {
int count = 0;
while (*str) {
if (!((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z'))) {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int nonLetters = countNonLetters(str);
printf("Number of non-letter characters: %d\n", nonLetters);
return 0;
}
15. 输入一个字符串,计算其中小写字母的数量
#include <stdio.h>
int countLowerCaseLetters(char *str) {
int count = 0;
while (*str) {
if (*str >= 'a' && *str <= 'z') {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int lowerCaseLetters = countLowerCaseLetters(str);
printf("Number of lowercase letters: %d\n", lowerCaseLetters);
return 0;
}
16. 输入一个字符串,计算其中大写字母的数量
#include <stdio.h>
int countUpperCaseLetters(char *str) {
int count = 0;
while (*str) {
if (*str >= 'A' && *str <= 'Z') {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int upperCaseLetters = countUpperCaseLetters(str);
printf("Number of uppercase letters: %d\n", upperCaseLetters);
return 0;
}
17. 输入一个字符串,计算其中元音字母的数量
#include <stdio.h>
int countVowels(char *str) {
int count = 0;
while (*str) {
if ((*str == 'a') || (*str == 'e') || (*str == 'i') || (*str == 'o') || (*str == 'u') ||
(*str == 'A') || (*str == 'E') || (*str == 'I') || (*str == 'O') || (*str == 'U')) {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int vowels = countVowels(str);
printf("Number of vowels: %d\n", vowels);
return 0;
}
18. 输入一个字符串,计算其中辅音字母的数量
#include <stdio.h>
int countConsonants(char *str) {
int count = 0;
while (*str) {
if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z') &&
(*str != 'a') && (*str != 'e') && (*str != 'i') && (*str != 'o') && (*str != 'u') &&
(*str != 'A') && (*str != 'E') && (*str != 'I') && (*str != 'O') && (*str != 'U')) {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int consonants = countConsonants(str);
printf("Number of consonants: %d\n", consonants);
return 0;
}
19. 输入一个字符串,计算其中字母和数字的总数
#include <stdio.h>
int countAlphanumeric(char *str) {
int count = 0;
while (*str) {
if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z') || (*str >= '0' && *str <= '9')) {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int alphanumeric = countAlphanumeric(str);
printf("Number of alphanumeric characters: %d\n", alphanumeric);
return 0;
}
20. 输入一个字符串,计算其中空格和标点符号的总数
#include <stdio.h>
int countSpacesAndPunctuation(char *str) {
int count = 0;
while (*str) {
if ((*str == ' ') || (*str == '.') || (*str == ',') || (*str == '!') || (*str == '?') ||
(*str == ';') || (*str == ':') || (*str == '-') || (*str == '(') || (*str == ')')) {
count++;
}
str++;
}
return count;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int spacesAndPunctuation = countSpacesAndPunctuation(str);
printf("Number of spaces and punctuation: %d\n", spacesAndPunctuation);
return 0;
}
21. 输入一个字符串,计算其中元音字母和辅音字母的总数
#include <stdio.h>
int countVowelsAndConsonants(char *str) {
int vowels = 0, consonants = 0;
while (*str) {
if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z')) {
if ((*str == 'a') || (*str == 'e') || (*str == 'i') || (*str == 'o') || (*str == 'u') ||
(*str == 'A') || (*str == 'E') || (*str == 'I') || (*str == 'O') || (*str == 'U')) {
vowels++;
} else {
consonants++;
}
}
str++;
}
return vowels + consonants;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int vowelsAndConsonants = countVowelsAndConsonants(str);
printf("Number of vowels and consonants: %d\n", vowelsAndConsonants);
return 0;
}
22. 输入一个字符串,计算其中元音字母和辅音字母的比率
#include <stdio.h>
float countVowelsAndConsonantsRatio(char *str) {
int vowels = 0, consonants = 0;
while (*str) {
if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z')) {
if ((*str == 'a') || (*str == 'e') || (*str == 'i') || (*str == 'o') || (*str == 'u') ||
(*str == 'A') || (*str == 'E') || (*str == 'I') || (*str == 'O') || (*str == 'U')) {
vowels++;
} else {
consonants++;
}
}
str++;
}
if (consonants == 0) {
return 0.0;
}
return (float)vowels / consonants;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
float ratio = countVowelsAndConsonantsRatio(str);
printf("Ratio of vowels to consonants: %.2f\n", ratio);
return 0;
}
23. 输入一个字符串,计算其中元音字母、辅音字母、空格和标点符号的总数
#include <stdio.h>
int countVowelsConsonantsSpacesPunctuation(char *str) {
int vowels = 0, consonants = 0, spaces = 0, punctuation = 0;
while (*str) {
if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z')) {
if ((*str == 'a') || (*str == 'e') || (*str == 'i') || (*str == 'o') || (*str == 'u') ||
(*str == 'A') || (*str == 'E') || (*str == 'I') || (*str == 'O') || (*str == 'U')) {
vowels++;
} else {
consonants++;
}
} else if (*str == ' ') {
spaces++;
} else if ((*str == '.') || (*str == ',') || (*str == '!') || (*str == '?') ||
(*str == ';') || (*str == ':') || (*str == '-') || (*str == '(') ||
(*str == ')')) {
punctuation++;
}
str++;
}
return vowels + consonants + spaces + punctuation;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
int total = countVowelsConsonantsSpacesPunctuation(str);
printf("Total number of vowels, consonants, spaces, and punctuation: %d\n", total);
return 0;
}
24. 输入一个字符串,计算其中元音字母、辅音字母、空格和标点符号的比率
#include <stdio.h>
float countVowelsConsonantsSpacesPunctuationRatio(char *str) {
int vowels = 0, consonants = 0, spaces = 0, punctuation = 0;
while (*str) {
if ((*str >= 'a' && *str <= 'z') || (*str >= 'A' && *str <= 'Z')) {
if ((*str == 'a') || (*str == 'e') || (*str == 'i') || (*str == 'o') || (*str == 'u') ||
(*str == 'A') || (*str == 'E') || (*str == 'I') || (*str == 'O') || (*str == 'U')) {
vowels++;
} else {
consonants++;
}
} else if (*str == ' ') {
spaces++;
} else if ((*str == '.') || (*str == ',') || (*str == '!') || (*str == '?') ||
(*str == ';') || (*str == ':') || (*str == '-') || (*str == '(') ||
(*str == ')')) {
punctuation++;
}
str++;
}
if (consonants == 0) {
return 0.0;
}
return (float)(vowels + spaces + punctuation) / consonants;
}
int main() {
char str[100];
printf("Enter a string: ");
scanf("%s", str);
float ratio = countVowelsConsonantsSpacesPunctuationRatio(str);
printf("Ratio of vowels, spaces, and punctuation to consonants: %.2f\n", ratio);
return 0;
}
25. 输入一个字符串,计算其中元音字母、辅音字母、空格和标点符号的百分比
”`c
#include
void countVowelsConsonantsSpacesPunctuationPercentage(char
