include"stdio.h"main(){inti,j,result;for(i=1;i<10;i++){for(j=1;j<10;j++){result=i*j;printf("%d*%d=%-3d",i,j,result);/*-3d表示左对齐，占3位*/}printf("\n");/*每一行后换行*/}system("pause");}

include"stdio.h"main(){longf1,f2;inti;f1=f2=1;for(i=1;i<=20;i++){printf("%12ld %12ld",f1,f2);if(i%2==0)printf("\n");/*控制输出，每行四个*/f1=f1+f2;/*前两个月加起来赋值给第三个月*/f2=f1+f2;/*前两个月加起来赋值给第三个月*/}system("pause");}

include"math.h"main(){intm,i,k,h=0,leap=1;printf("\n");for(m=101;m<=200;m++){k=sqrt(m);for(i=2;i<=k;i++)if(m%i==0){leap=0;break;}if(leap)/*内循环结束后，leap依然为1，则m是素数*/{printf("%-4d",m);h++;if(h%10==0)printf("\n");}leap=1;}printf("\nThe total is %d",h);system("pause");}

intmain(){staticintk[10];inti,j,n,s;for(j=2;j<1000;j++){n=-1;s=j;for(i=1;i<j;i++){if((j%i)==0){n++;s=s-i;k[n]=i;}}if(s==0){printf("%d is a wanshu: ",j);for(i=0;i<n;i++)printf("%d,",k[i]);printf("%d\n",k[n]);}}system("pause");}

intmain(){inta[4][4],b[4][4],i,j;/*a 存放原始数组数据， b 存放旋转后数组数据*/printf("input 16 numbers: ");/*输入一组数据存放到数组 a 中，然后旋转存放到 b 数组中*/for(i=0;i<4;i++)for(j=0;j<4;j++){scanf("%d",&a[i][j]);b[3-j][i]=a[i][j];}printf("array b:\n");for(i=0;i<4;i++){for(j=0;j<4;j++)printf("%6d",b[i][j]);printf("\n");}system("pause");}

intmain(){inti,j,a[6][6];for(i=0;i<=5;i++){a[i][i]=1;a[i][0]=1;}for(i=2;i<=5;i++)for(j=1;j<=i-1;j++)a[i][j]=a[i-1][j]+a[i-1][j-1];for(i=0;i<=5;i++){for(j=0;j<=i;j++)printf("%4d",a[i][j]);printf("\n");}system("pause");}

includeincludeintmain(){floata[4][5],sum1,sum2;inti,j;for(i=0;i<3;i++)for(j=0;j<4;j++)scanf("%f",&a[i][j]);for(i=0;i<3;i++){sum1=0;for(j=0;j<4;j++)sum1+=a[i][j];a[i][4]=sum1/4;}for(j=0;j<5;j++){sum2=0;for(i=0;i<3;i++)sum2+=a[i][j];a[3][j]=sum2/3;}for(i=0;i<4;i++){for(j=0;j<5;j++)printf("%6.2f",a[i][j]);printf("\n");}system("pause");}

includeintmain(){charc[200],c1;inti,j,k;printf("Enter a string: ");scanf("%s",c);k=strlen(c);for(i=0,j=k-1;i<k/2;i++,j--){c1=c[i];c[i]=c[j];c[j]=c1;}printf("%s\n",c);system("pause");}

includevoidinvert(char*s){inti,j,k;chart;k=strlen(s);for(i=0,j=k-1;i<k/2;i++,j--){t=*(s+i);*(s+i)=*(s+j);*(s+j)=t;}}main(){FILE*fp;charstr[200],*p,i,j;if((fp=fopen("p9_2.out","w"))==NULL){printf("cannot open the file\n");exit(0);}printf("input str:\n");gets(str);printf("\n%s",str);fprintf(fp,"%s",str);invert(str);printf("\n%s",str);fprintf(fp,"\n%s",str);fclose(fp);system("pause");}

includeintmain(){chars[80],c;intj,k;printf("\nEnter a string: ");gets(s);printf("\nEnter a character: ");c=getchar();for(j=k=0;s[j]!=\0;j++)if(s[j]!=c)s[k++]=s[j];s[k]=\0;printf("\n%s",s);system("pause");}

includevoidsort(int*x,intn){inti,j,k,t;for(i=0;i<n-1;i++){k=i;for(j=i+1;j<n;j++)if(x[j]>x[k])k=j;if(k!=i){t=x[i];x[i]=x[k];x[k]=t;}}}voidmain(){FILE*fp;int*p,i,a[10];fp=fopen("p9_1.out","w");p=a;printf("Input 10 numbers:");for(i=0;i<10;i++)scanf("%d",p++);p=a;sort(p,10);for(;p<a+10;p++){printf("%d ",*p);fprintf(fp,"%d ",*p);}system("pause");fclose(fp);}

includeintmain(){inta[10]={0,12,17,20,25,28,30};/*a[0]为工作单元，从 a[1]开始存放数据*/intx,i,j=6;/*j 为元素个数*/printf("Enter a number: ");scanf("%d",&x);a[0]=x;i=j;/*从最后一个单元开始*/while(a[i]>x){a[i+1]=a[i];i--;}/*将比 x 大的数往后移动一个位置*/a[++i]=x;j++;/*插入 x 后元素总个数增加*/for(i=1;i<=j;i++)printf("%8d",a[i]);printf("\n");system("pause");}

includereplace(char*s,charc1,charc2){while(*s!=\0){if(*s==c1)*s=c2;s++;}}main(){FILE*fp;charstr[100],a,b;if((fp=fopen("p10_2.out","w"))==NULL){printf("cannot open the file\n");exit(0);}printf("Enter a string:\n");gets(str);printf("Enter a&&b:\n");scanf("%c,%c",&a,&b);printf("%s\n",str);fprintf(fp,"%s\n",str);replace(str,a,b);printf("The new string is----%s\n",str);fprintf(fp,"The new string is----%s\n",str);fclose(fp);system("pause");}

main(){chars1[6]="thisis";chars2[5]="is";printf("%d\n",search(s1,s2));system("pause");}intsearch(chars1[],chars2[]){inti=0,j,len=strlen(s2);while(s1[i]){for(j=0;j<len;j++)if(s1[i+j]!=s2[j])break;if(j>=len)returni;elsei++;}return-1;}

structstudent{intnum;char*name;charsex;intage;}stu[5]={{1001,"lihua",F,18},{1002,"liuxing",M,19},{1003,"huangke",F,19},{1004,"fengshou",F,19},{1005,"Wangming",M,18}};main(){inti;structstudent*ps;printf("Num\tName\t\t\tSex\tAge\t\n");/*用指针变量输出结构体数组元素。 */for(ps=stu;ps<stu+5;ps++)printf("%d\t%-10s\t\t%c\t%d\t\n",ps->num,ps->name,ps->sex,ps->age);/*用数组下标法输出结构体数组元素学号和年龄。 */for(i=0;i<5;i++)printf("%d\t%d\t\n",stu[i].num,stu[i].age);system("pause");}

define NULL 0structstudent{intnum;char*name;intage;structstudent*next;};voidmain(){structstudenta,b,c,*head,*p;a.num=1001;a.name="lihua";a.age=18;/* 对结点成员进行赋值 */b.num=1002;b.name="liuxing";b.age=19;c.num=1003;c.name="huangke";c.age=18;head=&a;/* 建立链表， a 为头结点 */a.next=&b;b.next=&c;c.next=NULL;p=head;/* 输出链表 */do{printf("%5d,%s,%3d\n",p->num,p->name,p->age);p=p->next;}while(p!=NULL);system("pause");}

includeincludeincludemain(){chars[100];inti,j,n;printf("输入字符串：\n");gets(s);n=strlen(s);for(i=0,j=n-1;i<j;i++,j--)if(s[i]!=s[j])break;if(i>=j)printf("是回文串\n");elseprintf("不是回文串\n");system("pause");}

includevoidfun(inta[],intn){inti,j,t;for(i=0;i<=n-1;i++)for(j=0;j<i;j++)if(a[j]>a[j+1]){t=a[j];a[j]=a[j+1];a[j+1]=t;}}main(){inta[10]={12,45,7,8,96,4,10,48,2,46},n=10,i;FILE*f;if((f=fopen("myf2.out","w"))==NULL)printf("open file myf2.out failed!\n");fun(a,10);for(i=0;i<10;i++){printf("%4d",a[i]);fprintf(f,"%4d",a[i]);}fclose(f);system("pause");}

includedoublecountpi(doubleeps)/*eps 为允许误差*/{intm=1;doubletemp=1.0,s=0;while(temp>=eps){s+=temp;temp=temp*m/(2*m+1);m++;}return(2*s);}main(){FILE*fp;doubleeps=1e-5,pi;if((fp=fopen("p7_3.out","w"))==NULL){printf("cannot open the file\n");exit(0);}pi=countpi(eps);printf("pi=%lf\n",pi);fprintf(fp,"pi=%lf\n",pi);fclose(fp);system("pause");}