C语言循环例题

1.//输出a和b之间的所有素数, 10个素数为一行输出#include<stdio.h>#include<stdlib.h>#include<math.h>int panDuanSuShu(int x) //判断x是否是素数{int i,m,flag; //flag为1表示是素数，flag为0表示不是素数 m=(int)sqrt(x);if(x==2){ flag=1;}else{for(i=2;i<=m;i++){if(x%i==0){flag=0;break;}}if(i>m){ flag=1; }}return flag;}int shuChuSuShu(int a,int b){int i,k=0;//i是循环变量，k表示已经输出了k个素数for(i=a;i<=b;i++){if(panDuanSuShu(i)==1){printf("%6d",i);k++;if(k%10==0){ printf("\n");}}}printf("\n");return k;}int main(){int a,b,t;while(a<2||b<2){printf("重新输入n和m：");scanf("%d%d",&a,&b);}if(a>b){ t=a;a=b;b=t; }printf("%d和%d之间共有%d个素数",a,b,shuChuSuShu(a,b));printf("\n\n");return 0;}2.//用户输入2个数，输出这2个数之间所有的超素数//超素数(质数)的概念：7193是素数，719是素数，71是素数，7是素数，则7193是素数#include<stdio.h>#include<stdlib.h>#include<math.h>int isPrime(int n)//判断某数是否是素数{int i,f,m=(int)sqrt(n);if(n==1) f=0;else{for(i=2;i<=m;i++){if(n%i==0)break;}if(i>m) f=1;else f=0;}return f;}int supperPrime(int n)//判断某数是否是超素数{int t=n;while(t>0){if(isPrime(t)==1)t=t/10;elsebreak;}}void printSupperPrime(int a,int b)//输出a到b之间所有的超素数{int i,m=0;for(i=a;i<=b;i++){if(supperPrime(i)){ printf("%8d",i);m++;if(m%5==0)printf("\n");}}printf("\n");}int main(){int a,b,t;printf("input a,b:");scanf("%d%d",&a,&b);while(a<2 || b<2){printf("input a,b:");scanf("%d%d",&a,&b);}if(a>b) {t=a;a=b;b=t;}printSupperPrime(a,b);printf("\n");//system("pause");return 0;}3.//满足a*a+b*b==c*c的a,b,c三个数，称为勾股数//编程输出100以内的所有勾股数#include<stdio.h>#include<stdlib.h>int gouGuShu(){int x=0;for(int a=1;a<=100;a++)for(int b=a;b<=100;b++)for(int c=b;c<=100;c++)if(x%4==0)printf("\n");printf("%4d%4d%4d ",a,b,c);x++;}return x;}int main(){printf("\n\n 100以内的勾股数共有：%d个。

\n",gouGuShu());// system("pause");return 0;}4.//有一堆桃子，第一天猴子吃掉桃子的一半又多吃1个，第二天猴子再吃掉桃子的一半又多吃一个//第10天只剩下1个桃子，问最初有多少个桃子#include<stdio.h>#include<stdlib.h>int houZiChiTaoZi(){int day=10,x1,x2=1;while(day>1){x1=(x2+1)*2;x2=x1;day--;}return x1;}int main(){printf("最初桃子有%d个\n",houZiChiTaoZi());//system("pause");return 0;}5.//由用户输入一个年份，再输入该年的元旦是星期几，再输入一个月份，则打印输出该月的日历。

//例如：输入年份是2000年，输入元旦为星期6，输入月份为3，则输出：//3月日一二三四五六// 1 2 3 4// 5 6 7 8 9 10 11// 12 13 14 15 16 17 18// 19 20 21 22 23 24 25// 26 27 28 29 30 31#include<stdio.h>int LeepYear(int y)//判断某年是否是闰年{if(y%4==0&&y%100!=0||y%400==0)return 1;elsereturn 0;}int HowManydays(int y,int m)//判断该月有多少天{int thisMonthDays;switch(m){case 1:case 3:case 5:case 7:case 8:case 10:case 12: thisMonthDays=31;break;case 4:case 6:case 9:case 11:thisMonthDays=30;break;case 2: if(LeepYear(y)==1) thisMonthDays=29;else thisMonthDays=28;}return thisMonthDays;}//whichWeek函数判断该月的1号是星期几int whichWeek(int y,int m,int w) //w表示该年的元旦是星期几{int febDay;//存放2月份有多少天int days;//存放该月的1号距离元月1号有多少天int thisWeek;//存放该月的1号是星期几if(LeepYear(y)){ febDay=29;}else{ febDay=28; }switch(m){case 1: days=0;break;case 4: days=2*31+febDay;break;case 5: days=2*31+30+febDay;break;case 6: days=3*31+30+febDay;break;case 7: days=3*31+2*30+febDay;break;case 8: days=4*31+2*30+febDay;break;case 9: days=5*31+2*30+febDay;break;case 10: days=5*31+3*30+febDay;break;case 11:days=6*31+3*30+febDay;break;case 12:days=6*31+4*30+febDay;break;}thisWeek=(days+w)%7;return thisWeek;}//shuChuRiLi函数的功能是输出日历void shuChuRiLi(int year,int month,int week) //week表示该年的元旦是星期几{int ThisMonthDay,ThisWeek,d,i;ThisMonthDay=HowManydays(year,month);//计算这个月有多少天ThisWeek=whichWeek(year,month,week);//计算这个月的1号是星期几printf("\n\n");printf("%4d月日一二三四五六\n",month);printf("%6c",' ');d=1;for(i=0;i<ThisWeek;i++) //输出1号前面的空格printf("%6c",' ');for(i=ThisWeek;i<=6;i++,d++) //输出1号所在的那1行日历printf("%6d",d);while(d<=ThisMonthDay){if(i%7==0){printf("\n");printf("%6c",' ');}printf("%6d",d);d++;i++;}printf("\n\n");}int main(){int year=-20,month=13,week=9;printf("请输入年份：");scanf("%d",&year);}while(month>12||month<1){printf("请输入月份：");scanf("%d",&month);}while(week>7||week<1){printf("该年的元旦是星期几？");scanf("%d",&week);}shuChuRiLi(year,month,week);system("pause");return 0;}6.//输出三种形式的九九乘法口诀表#include<stdio.h>#include<stdlib.h>void chengFaKouJueBiao1(){int i,j;printf(" *|");for(i=1;i<=9;i++)printf("%4d",i);printf("\n");for(i=1;i<=40;i++)printf("-");printf("\n");for(i=1;i<=9;i++){printf("%2d|",i);for(j=1;j<=9;j++){printf("%4d",i*j);}printf("\n");}printf("\n\n");}void chengFaKouJueBiao2(){for(i=1;i<=9;i++)printf("%4d",i);printf("\n");for(i=1;i<=9;i++){printf("%2d",i);for(j=1;j<=i;j++){printf("%4d",i*j);}printf("\n");}printf("\n\n");}void chengFaKouJueBiao3(){int i,j;printf("\n");for(i=1;i<=9;i++){for(j=1;j<=i;j++){printf("%d*%d=%-4d",i,j,i*j);}printf("\n");}printf("\n\n");}int main(){chengFaKouJueBiao1();chengFaKouJueBiao2();chengFaKouJueBiao3();// system("pause");return 0;}7.//用户输入三角形的高度，输出由*构成的三角形。