C语言例题整理

顺序结构程序设计已知三角形的底边为20，高为10，求其面积。

#include<stdio.h>void main(){float a,h,s;a=20;h=10;s=1.0/2*a*h;/*1.0/2不能写作1/2*/printf("s=%f\n",s);}从键盘输入三角形的底边及高的长度，求其面积。

#include<stdio.h>void main(){float a,h,s;scanf("%f%f",&a,&h);s=1.0/2*a*h; /*1.0/2不能写作1/2*/printf("s=%f\n",s);}变量作用域# include <stdio.h>int count; /* count是全局变量*/void func1( ); /* 函数声明*/void func2( );void main( ){count = 100;func1();}void func1() /* 函数定义*/{int temp; /* temp是局部变量*/ temp = count;func2();printf(" count is %d\n",count); /* 打印100 */func2();}void func2(){int count; /* 定义局部变量count */for(count = 1; count <20; count++)printf("."); /*打印出"." */printf("\n");}多文件f1.c#include<stdio.h>extern a;void main(){intx=7,y=8,result1,result2;result1=(x+y)*a+max(x,y*a);a-=3;result2=min(a,max(x,y));printf("result1=%d,result2=%d\n",result1,result2);}f2.cextern int a=10;int max(int x,int y){return x>y?x:y;}int min(int x,int y){return x<y?x:y;}分段函数#include<stdio.h>void main(){double x,y;scanf ("%lf",&x);if(x>=1)if(x>=10)y=3*x-14;elsey=2*x-1;elsey=x;printf("%lf\n",y);}冒泡1#include<stdio.h>#define N 5void main(){int i,j,t,a[N];for(i=0;i<N;i++)scanf("%d",&a[i]);for(i=0;i<N-1;i++)for(j=0;j<N-1-i;j++)if(a[j]<a[j+1]){t=a[j];a[j]=a[j+1];a[j+1]=t;}for(i=0;i<N;i++)printf("%d\t",a[i]);printf("\n");}冒泡2#include<stdio.h>#define N 5void sort(int a[N]){int i,j,t;for(i=0;i<N-1;i++)for(j=0;j<N-1-i;j++)if(a[j]<a[j+1]){t=a[j];a[j]=a[j+1];a[j+1]=t;}}void main(){int i,a[N];for(i=0;i<N;i++)scanf("%d",&a[i]);sort(a);for(i=0;i<N;i++)printf("%d\t",a[i]);printf("\n");}逆序三位数#include<stdio.h>void main(){int x,y=0,m;printf("请输入一个三位数：");scanf("%d",&x);while(x){m=x%10;y=10*y+m;x=x/10;}printf("y=%d\n",y);}闰年#include<stdio.h>int isleap(int year){if(year%400==0||year% 4==0&&year%100!=0)return 1;elsereturn 0;}void main(){int year,n=0;for(year=1900;year<=2010;year++){if(isleap(year)){printf("%d\t",year);n++;if(n%5==0)printf("\n");}}printf("\n");}数组参数1/*编写一函数，该函数的功能是*/#include<stdio.h>#define M 3#define N 4void conert(int a[][N],intb[][N]);void main(){int i,j;intb[M][N],a[M][N]={1,2,-4,6,-9,11,32,-45,-22,-7,67,91};conert(a,b);for(i=0;i<M;i++){for(j=0;j<N;j++)printf("%d\t",b[i][j]);printf("\n");}}void conert(int a[][N],intb[][N]){int i,j;for(i=0;i<M;i++){for(j=0;j<N;j++){if(a[i][j]<0)b[i][j]=-1;elseif(a[i][j]>0)b[i][j]=1;elseb[i][j]=0;}}}2#include<stdio.h>#define N 12double add(double a[],intn,int m);void main(){doublea[N]={1,2,-4,6,-9,11,32,-45,-22,-7,67,91},sum;sum=add(a,3,4);printf("%lf\n",sum);}double add(double a[],intn,int m){int i;double s=0;for(i=n;i<n+m;i++){s+=a[i];}return s;}素数/*编写判断素数的函数，再调用该函数判断1937是否是素数。

*/#include<stdio.h>int isprime(int n){int i;for(i=2;i<n;i++)if(n%i==0)return 0;elsecontinue;return 1;}void main(){if(isprime(1937))printf("prime\n");elseprintf("noprime\n");}统计单词#include<stdio.h>void main(){char string[1024];int i,num=0,word=0;char c;gets(string);for(i=0;(c=string[i])!='\ 0';i++)if(c==' ')word=0;else{if(word==0){num++;word=1;}}printf("%d\n",num);}选择排序#include<stdio.h>#include<string.h>void nsort(int*p,int n){int i,j,min;for(i=0;i<n-1;i++){min=i;for(j=i+1;j<n;j++){if(p[min]>p[j]){min=j;}}if(min!=i){int t;t=p[min];p[min]=p[i];p[i]=t;}}}void ssort(char**p,int n){int i,j,min;for(i=0;i<n-1;i++){min=i;for(j=i+1;j<n;j++){if(strcmp(p[min],p[j])>0)min=j;}if(min!=i){char*q;q=p[min];p[min]=p[i];p[i]=q;}}}void main(){inti,a[]={23,6,78,15,88,123};char*name[]={"FORTRAN","BASIC","C++","Java","VB","C"};nsort(a,6);for(i=0;i<6;i++)printf("%d\t",a[i]);printf("\n");ssort(name,6);for(i=0;i<6;i++)puts(name[i]);}/*输入一个字符串，将其中连续的数字作为一个整数，依次存放在一个数组中，统计共有多少个整数，并输出这些整数*/#include<stdio.h>void main(){char str[80];intnumber[20],i=0,j=0,n=0,flag=0;gets(str);while(str[i]!='\0'){if(str[i]>='0'&&str[i]<='9'){n=10*n+(str[i]-'0');if(flag==0)flag=1;}else{if(flag){number[j]=n;j++;n=0;flag=0;}}i++;}if(flag)number[j]=n;for(i=0;i<=j;i++)printf("%d\t",number[i] );printf("\n");}最大公约数#include<stdio.h>void main(){int m,n,r,p;scanf("%d%d",&m,&n) ;p=m*n;while((r=m%n)!=0){m=n;n=r;}printf("最大公约数是：%d\n",n); /*r=0时的除数是最大公约数*/printf("最小公倍数是：%d\n",p/n); /*两数的积除以最大公约数等于最小公倍数*/}插入#include<stdio.h>void main(){inta[8]={2,32,45,67,88,91,94};int i,j,x;for(i=0;i<7;i++){printf("%d ",a[i]);}printf("\n");scanf("%d",&x);for(i=0;i<7;i++){if(x<a[i])break;}for(j=7;j>i;j--){a[j]=a[j-1];}a[i]=x;for(i=0;i<8;i++){printf("%d ",a[i]);}printf("\n");}查找#include<stdio.h>void main(){inta[]={3,6,8,10,12,33,38,56,60};intx,top=0,bottom=8,mid;scanf("%d",&x);while(bottom>=top){mid=(top+bottom)/2;if(x>a[mid])top=mid+1;elseif(x<a[mid])bottom=mid-1;else{printf("%d在数组中找到，下标为%d\n",x,mid);return;}}printf("%d在数组中没找到!\n");}带参数的main#include <stdio.h>void main(intargc,char*argv[]){int i;printf("argc=%d\n",argc);for(i=0;i<argc;i++){printf("argv[%d]=%s\n",i,argv[i]);}}共用体的意义#include <stdio.h>void main(){int i;union data{int a;char b;char c[20];}x;scanf("%d",&x.a);printf("%d\n",x.a);scanf("%c",&x.b);printf("%c\n",x.b);scanf("%s",x.c);printf("%s\n",x.c);}删除#include<stdio.h>void main(){inta[7]={2,32,45,67,88,91,94};int j,x;for(j=0;j<7;j++){printf("%d ",a[j]);}printf("\n");scanf("%d",&x);for(j=x;j<6;j++){a[j]=a[j+1];}for(j=0;j<6;j++){printf("%d ",a[j]);}printf("\n");}文件块操作#include<stdio.h>struct student{int num;char name[20];char sex;int age;float score;};struct students1,stu[4]={ {11301,"ZhangPing",'F',19,496.5},{11302,"WangLi",'F',20,483},{11303,"LiuHong",'M',19,503},{11304,"SongRui",'M',19,471.5}};void main(){FILE*fp;if((fp=fopen("c:\\abc.txt","w"))==NULL){printf("file openerror!\n");exit(1);}fwrite(stu,sizeof(structstudent),4,fp);fclose(fp);if((fp=fopen("c:\\abc.txt","r"))==NULL){printf("file openerror!\n");exit(1);}fseek(fp,sizeof(structstudent),0);fread(&s1,sizeof(structstudent),1,fp);printf("%d\n",s1.num);}杨辉三角形#include<stdio.h>#define N 10void main(){int i,j,k;int a[N][N];printf("\n");for(i=0;i<N;i++)/* 生成杨辉三角形每行的首、尾元素值*/{a[i][0]=1;a[i][i]=1;}for(i=2;i<N;i++)/* 生成杨辉三角形其他元素值*/for(j=1;j<i;j++)a[i][j]=a[i-1][j-1]+a[i-1][j];for(i=0;i<N;i++)/* 输出杨辉三角形*/{for(k=2;k<N-i;k++)printf(" ");for(j=0;j<=i;j++)printf("%6d",a[i][j]);printf("\n");}}设计一个函数voidchange(char*s)，将字符串s中下标为偶数的字符移到左边，下标为奇数的字符移到右边。