演示1#include <stdio.h>void print_star(void) printf("*n");void print_welcome(void) printf("C language,welcome!n");void main() print_star(); print_welcome(); print_star(); getchar();演示2#include "stdio.h"int sum(int i,int j) return(i + j);void main() int n1,n2; printf("input 2 numbers:n"); scanf("%d%d",&n1,&n2); printf("the sum = %dn",sum(n1,n2); getchar();演示3#include "stdio.h"int maxnum(int,int,int);main() int a,b,c; printf("Please enter 3 numbers:n"); scanf("%d,%d,%d",&a,&b,&c); printf("Maxnum is %dn",maxnum(a,b,c); return 0;int maxnum(int x,int y,int z) int max=x; if(y>max) max = y; if(z>max) max = z; return max;演示4#include <stdio.h>int s1(int n)int j,s; s=0; for(j=1;j<=n;j+) s=s+j; return s;int sum(int n)int i,s=0;for(i=1;i<=n;i+)s=s+s1(i);return s;void main()int n;printf("n:");scanf("%d",&n);printf("s=%dn",sum(n);演示5#include <stdio.h>void func(int n)int i;for(i=n-1;i>=1;i-)n=n+i;printf("n=%dn",n);void main()int n;printf("Input n:");scanf("%d",&n);func(n);printf("n=%dn",n);演示6#include <stdio.h>void swap(int a,int b)int temp;temp=a;a=b;b=temp;printf("swap : a=%d,b=%dn",a,b);void main()int a,b;a=3;b=10;swap(a,b);printf("a=%d,b=%dn",a,b);演示7#include <stdio.h>int func(int a,int b)int c;c=a+b;return c;void main()int x=6,y=7,z=8,r;r=func(x-,y+,x+y),z-);printf("%dn",r);演示8#include <stdio.h>max(float x,float y)return x>y? x:y;void main()printf("%dn",max(2,3.5);演示9#include <stdio.h>int sum(int n)int i,s=0;for(i=0;i<=n;i+)s=s+i;return s;void main() int m,sn; scanf("%d",&m); sn=sum(m); printf("the sum is %dn",sn);演示10#include <stdio.h>void swap(int x,int y);int main() int a,b; printf("input 2 numbers :n"); scanf("%d,%d",&a,&b); printf("input number is:a=%d,b=%d n",a,b); swap(a,b); printf("input 2 numbers is:a=%d,b=%dn",a,b); return 0;void swap(int x,int y) int temp; temp = x; x = y; y = temp; printf("swap number is : x = %d,y = %d n",x,y);演示11#include "stdio.h"#define K 3#define N 5long f2(int n,int k) long power = n; int i; for(i=1;i<k;i+) power *=n; return power;long f1(int n,int k) long sum = 0 ; int i; for(i=1;i<=n;i+) sum = sum + f2(i,k); return sum;int main(void) printf("sum of %d power of integer from 1 to %d = ",K,N); printf("%ldn",f1(N,K); return 0;演示12#include <stdio.h>int min(int a,int b);int main(void) int j,k,mininum; printf("input 2 integers:"); scanf("%d,%d",&j,&k); mininum = min(j,k); printf("n of the two values %d and %d,the mininum is %dn",j,k,mininum); return 0;int min(int a,int b) if(a<b) return a; else return b;演示13#include <stdio.h>int func(int a,int b);void main() int k=4,m=1,p;p=func(k,m); printf("%dn",p);int func(int a,int b) int m=0,i=2; i+=m+1; m=i+a+b; return m;演示14#include <stdio.h>int max(int x,int y)int z;z=x>y?x:y;return z;void main()extern int A,B; /聲明外部變量printf("%dn",max(A,B);int A=13,B=-8; /定義外部變量演示15#include <stdio.h>int f1(int xb) extern int xa; return (xa*xb);int main(void) extern int xb; int xa = 5; printf("xa=%d,xb=%d,result=%d",xa,xb,f1(xa); return 0;int xa = 3,xb = 4;演示16#include <stdio.h>void num()extern int x,y;int a=15,b=10;x=a-b;y=a+b;int x,y;void main()int a=7,b=5;x=a+b;y=a-b;num(); printf("%d,%dn",x,y);演示17#include <stdio.h>void main() void swap(); extern int a,b;a=3;b=10;swap();printf("a=%d,b=%dn",a,b);int a,b;void swap()int temp;temp=a;a=b;b=temp;演示18#include <stdio.h>void auto_static(void) int var_auto = 0; static int var_static = 0; printf("var_auto = %d,var_static = %dn",var_auto+,var_static+);void main() int i; for (i=0;i<3;i+) auto_static();演示19#include <stdio.h>void swap(int x,int y) int t; t=x;x=y;y=t; void main() int a,b; scanf("%d,%d",&a,&b); swap(a,b); printf("%d,%dn",a,b);-#include <stdio.h>int x,y;void swap(int ，,int) int t; t=x;x=y;y=t; void main() scanf("%d,%d",&x,&y); swap(x,y); printf("%d,%dn",x,y);#include <stdio.h>int x,y;void swap(int x,int y) int t; t=x;x=y;y=t; void main() scanf("%d,%d",&x,&y); swap(x,y); printf("%d,%dn",x,y);-演示20#include <stdio.h>int fac(int n) static int f=1; f=f*n; return f;void main() int i; for(i=1;i<=5;i+) printf("%d!=%dn",i,fac(i);演示21#include "stdio.h"int main(void) int a = 2; int p = a; printf("%dn",a); int a =7; printf("%dn",a); printf("%dn",p); printf("%dn",+a); return 0;演示22#include <stdio.h>int func(int a,int b);void main() int k=4,m=1,p;p=func(k,m);printf("%d,",p);p=func(k,m);printf("%dn",p);int func(int a,int b) static int m=0,i=2; i+=m+1; m=i+a+b; return m;演示23#include <stdio.h>f(int n)int c;if(n=6)c=1;elsec=(f(n+1)+1)*2;return c;void main() printf("%dn",f(1);演示24#include <stdio.h>long power(int n) long f; if(n>1) f=power(n-1)*n; else f=1; return f;main() int n; long x; printf("input an integer number:n"); scanf("%d",&n); x=power(n); printf("%d!=%ldn",n,x); getchar();演示25#include <stdio.h>int fact()static int i=5;if(i=0) return 1;elsei-;return (i+1)*fact();void main() printf("fact=%dn",fact();演示26#include <stdio.h>int fun(int k);int w=3;void main()int w=10;printf("%dn",fun(5)*w);int fun(int k)if(k=0) return w;return(fun(k-1)*k);演示27#include <stdio.h>int fac(int n) register int i,f=1; for(i=1;i<=n;i+) f=f*i; return f;main() int i; for(i=1;i<=5;i+) printf("%d!=%dn",i,fac(i);演示28#include <stdio.h>age(int n) int c; if(n=1)c=10; else c=age(n-1)+2; return c;void main() printf("%dn",age(5);演示29#include <stdio.h>#define PI 3.14#define circuit(r) 2*PI*r#define area(r) PI*r*rvoid main() float ra,c,a;scanf("%f",&ra);c=circuit(ra);a=area(ra);printf("ra=%f,c=%f,a=%f",ra,c,a);漢諾塔（演示30）#include "stdio.h"void move(int,char,char,char);int main(void) int n; printf("input n disk on tower A:n"); scanf("%d",&n); move(n,A,B,C); getchar(); return 0;void move(int n,char a,char b,char c) static int step=1; if(n=1) printf("step %d :move disk form %c -> %cn",step+,a,c); else move(n-1,a,c,b); move(1,a,b,c); move(n-1,b,a,c); 演示31#define LETTER 1#include "stdio.h"void main()char str20="C Language",c;int i;i=0;while(c=stri)!=0)i+;#if LETTERif(c>=a&&c<=z)c=c-32;#elseif(c>=A&&c<=Z)c=c+32;#endifprintf("%c",c);#include <stdio.h>long f(int n)if(n=1|n=2)return 1;else return f(n-1)+f(n-2);void main()long n;printf("input n:n");scanf("%d",&n);printf("the number is %dn",f(n);