c语言简单程序---初学者

素数的筛选 include include define N 1000 int main int argc char argv int i j num N for i 0 i N i num i i 1 for i 1 i int sqrt double N i if num i for j i 1 j N j if num j if num j num i 0 num j 0 for i 1 i N i if num i printf d num i return 0 输出时分秒 include main int x s t d scanf d s x 60 t x 60 60 d x 60 60 printf d 时 d 分 d 秒 d t s 三个数的交换 include void main int a b c t scanf d d d printf The original number a d b d c d n a b c t a a b b t t a a c c t printf after swap a d b d c d a b c switch 语句的运用 include main int a m printf please input a number scanf d switch a 10 case 10 case 9 m 5 break case 8 m 4 break case 7 m 3 break case 6 m 2 break default m 1 printf m d m 判断奇数和偶数 include main int x printf Please input a number scanf d if x 2 0 printf this is a oushu else printf this is a jishu 小写改大写 若是大写则不变 include main char c1 c2 printf Input a letter n scanf c c2 a c1 printf c c2 getchar return 0 输入一个数 输出这个数是几位数 include main int x n printf please input a number scanf d n 0 while x 0 x x 10 n printf d n 输入一个数 判断它是几位数 然后逆序输出 include int main int num int len 0 int temp 0 printf Please input a number n scanf d while num 10 0 temp temp 10 num 10 len num num 10 printf length d n len printf Reverse is d temp 打印水仙花数 include main int x a b c for x 100 x 999 x a x 10 b x 10 10 c x 100 if x a a a b b b c c c printf 5d x printf n 判断闰年 include stdio h main int k flag n 0 for k 1980 k 2880 k flag k 4 0 if flag printf 5d k n if n 10 0 printf n printf n 求 1 3 5 7 99 101 的值 include main int sum i t sum 1 t 1 for i 3 i 101 i i 2 t t sum sum t i printf sum d sum 求前 n 项和 include main float s t int n i fz fm s 0 fz 2 fm 1 printf Enter n scanf d for i 1 i n i t 1 0 fz fm s s t fz fz fm fm fz fm printf s f n s 开发一个程序求全班学生某门课的平均成绩 要求程序每次运行时班级人数可为任意 用标记值来指示数据输入的结束 include main float average total int counter score total 0 0 counter 0 printf 输入成绩 1 表示结束 scanf d while score 1 用 1 表示输入的结束 同时循环输入分数 total total score counter printf 输入下一个成绩 1 表示输入结束 scanf d if counter 0 average total counter printf 全班平均成绩为 2f n average else printf 没有输入成绩 n return 0 求二元一次方程的根 include include main float a 4 b 40 c 91 float x1 x2 float delta delta sqrt b b 4 0 a c x1 b delta 2 0 a x2 b delta 2 0 a printf x1 f x2 f n x1 x2 if 语句的运用 include main int a b c s w t s w t 0 a 1 b c 3 if c 0 s a b if a0 if c0 w a b else t c printf s d w d t d s w t 输入学生的生日 输出他的实足年龄 include main int y0 m0 d0 y1 m1 d1 age printf nplease input birthday yyyy mm dd scanf d d d printf nplease input current day yyyy mm dd scanf d d d if m1 m0 m1 m0 else age y1 y0 1 printf age d n age 指针变量作为函数参数 实现两数的交换 include void sswap int x int y main int a 10 b 20 printf before swap a d b d n a b sswap printf after swap a d b d n a b void sswap int x int y int t t x x y y t 通过函数调用输出两个实型数中最大的一个 include float f float px float py if px py return px return py main float x 10 0 y 20 0 a printf a f b f max f n a b f a b 计算并输出一个数组中所有元素的和 最大值 最小值 值为奇数的元素个数 编写一个函数 将一个字符串中的字符全部转成大写 include void Lower2Upper char str char p str while p 0 if p a p p 32 p main char s 10 Hello int i Lower2Upper s for i 0 i 10 i printf c s i 计算一个字符在一个字符串中出现的次数 include int count char ch char str char p str int num 0 while p 0 if p ch num return num main char ah a char s haowareayou printf the number is printf d n count a s 删除一维数组中所有相同的数 include void unique int a int n int k 1 int i m m a 0 for i 0 im a k a i m a i n k main int a 10 int n 10 i printf input a list number for i 0 i n i scanf d printf Before delete n for i 0 i n i printf d a i unique a printf after delete n for i 0 i n i printf d a i printf n 将字符串按字典顺序输出 include include define N 5 void sort char name int n void prn char name int n void main char name China America Australia France German sort name N prn name N void sort char name int n char pt int i j k for i 0 i n 1 i k i for j i 1 j0 k j if k i pt name i name i name k name k pt void prn char name int n int i for i 0 i n i printf s n name i 有 n 个学生 每个学生考 m 门课程 要求编一程序 能检查 n 个学生有无不及格的课程 如果有某一学生有一门或一门以上课程不及格 就输出该学生的号码和其全部成绩 include define N 5 define M 4 int col void prt float s int no int len main float a N M 78 99 89 87 67 59 87 77 86 53 59 95 77 88 57 95 78 75 87 95 score a N M void score float p M in