C/C++语言练习题

1.打印直角三角形

2.判断2000年到2500年有多少次闰年。

3.用三种循环while、for、do while 求1-100的和

4. 已知三个数a、b、c找最大值放在max中。

5.成绩分级：输入你的成绩90分以及以上等级为A,80-90分等级为B,70-80等级为c,70-60等级为D,60以下等级为E。

6.编写一个程序，用while循环，该程序读取整数，直到输入0，输入终止后，程序应该报告输入的偶数总数（不包括0），偶数平均值，输入的奇数总数以及奇数的平均值。

7.遍历打印出数组的地址，以及数组中各元素的地址。

8.找出二维数组中最大的元素。

9.大小写字母转换

10.打印平行四边形

11.字符串翻转

12.a++与++a，先从右到左运算，再从左到右赋值。a++先赋值再运算，++a先运算再赋值。

13.利用指针交换两个变量的值。

14.用指针找出一个数组中最大和最小的元素。

15.代码实现strcpy和strcat

16 去掉一段字符串中的空格

17.函数封装strcat、strcpy

18.函数封装字符串反转

19.函数指针，封装四则运算。

20.使用函数指针数组封装加减法

21.函数封装完成输入一个数，实现阶乘的功能。

22.递归实现阶乘

24.结构体练习

25.输入一个100 - 1000的数，判断该数是否为水仙花数。

26.输入一个数，数组按该数进行移动，并且打印。

27.将下列按照国家名字排序 china japan italy frech egland

28.随机输入10个整数，将他们按从小到大排序

1.打印直角三角形

#include <stdio.h>
int main()
{int i, j;int line;printf("请输入三角形的行数：");scanf("%d", &line);for (i = 0; i <= line; i++) //控制行数{for (j = 0; j <= i; j++) //控制*的个数 {printf("*");}printf("\n");}return 0;
}

效果如下

需要理解for循环、for循环嵌套每一步的执行过程，以及*如何限制，“\n”换行该如何打印。

2.判断2000年到2500年有多少次闰年。

#include <stdio.h>
int main()
{int year = 2000;int count = 0; for(; year <= 2500;year++){if(year % 4 == 0 && (year % 100 != 0 || year % 400 == 0)){printf("%d年是润年\n",year);count++;}else{printf("%d年非闰年\n",year); }}printf("2000-2500年有%d次闰年\n",count);return 0;
}

需要知道如何判段该年是不是闰年，并且计数，且理解for循环

3.用三种循环while、for、do while 求1-100的和

do while

  #include <stdio.h>int main(){int i = 0;int sum = 0;do{sum += i;i++;}while(i <= 100);printf("thr sum of 100 is %d\n ",sum);return 0;}

while

  #include <stdio.h>int main(){int i = 0;int sum = 0;while(i<=100){sum += i;i++;}printf("thr sum of 100 is %d\n ",sum);return 0;}

for

  #include <stdio.h>int main(){int i = 0;int sum = 0;for(;i <= 100; i++){sum += i;}printf("thr sum of 100 is %d\n ",sum);return 0;}

很简单，熟悉几个while、for、do while的格式即可。

4. 已知三个数a、b、c找最大值放在max中。

#include <stdio.h>
int main()
{int a,b,c,max;printf("请输入三个数：");scanf("%d %d %d",&a,&b,&c);if(a > b && a > c){max = a;printf("三个数中%d最大",a);} if(b > a && b > c){max = b;printf("三个数中%d最大",b);} if(c > b && c > a){max = c;printf("三个数中%d最大",c);}     return 0;
}

5.成绩分级：输入你的成绩90分以及以上等级为A,80-90分等级为B,70-80等级为c,70-60等级为D,60以下等级为E。

#include <stdio.h>
int main()
{float score;printf("请输入您的成绩：");scanf("%f",&score);if(score < 0 || score > 100){printf("socre is invalid\n");return 0;}if(score >= 90){printf("您的成绩等级为：A");}else if(score < 90 && score >= 80){printf("您的成绩等级为：B");}else if(score < 80 && score >= 70){printf("您的成绩等级为：C");}else if(score < 70 && score >= 60){printf("您的成绩等级为：D");}else{printf("您的成绩等级为：E");}return 0;
}

#include <stdio.h>
int main()
{float score;printf("请输入您的成绩：");scanf("%f",&score);if(score < 0 || score > 100){printf("socre is invalid\n");return 0;}int grade;grade = score / 10;switch(grade){case 9:printf("A\n");break;case 8:printf("B\n");break;case 7:printf("C\n");break;case 6:printf("D\n");break;default:printf("E\n");}return 0;}

6.编写一个程序，用while循环，该程序读取整数，直到输入0，输入终止后，程序应该报告输入的偶数总数（不包括0），偶数平均值，输入的奇数总数以及奇数的平均值。

#include <stdio.h>
int main()
{int num,sum1,sum2,count1,count2;float avg1,avg2;count1 = 0;count2 = 0;printf("请输入数：\n");scanf("%d",&num);while(num != 0){if(num % 2 == 0){sum1 += num;count1++;}else{sum2 += num;count2++;}    scanf("%d",&num);         }while(num == 0){avg1 = 1.0*sum1/count1;avg2 = 1.0*sum2/count2;printf("输入的偶数有%d个，偶数平均值为%f\n",count1,avg1);printf("输入的奇数有%d个，奇数平均值为%f\n",count2,avg2);break;}return 0;
}

7.遍历打印出数组的地址，以及数组中各元素的地址。

#include <stdio.h>
int main()
{int i,a[6];int j,b[6];printf("start address = %p\n",a);for(i = 0;i < sizeof(a) / sizeof(int);i++){printf("%p ",&a[i]);}printf("\ntotal:%d bytes\n",sizeof(a));printf("start address = %p\n",b);for(i = 0;i < sizeof(b) / sizeof(int);i++){printf("%p ",&b[i]);}printf("\ntotal:%d bytes\n",sizeof(b));return 0;
}

8.找出二维数组中最大的元素。

#include <stdio.h>
int main()
{int max,i,j;int a[3][4] = {{66,99,88,44},{110,120,336}};max = a[0][0];for(i = 0; i < 2; i++){for(j = 0;j < 3; j++){//遍历二维数组 if(a[i][j] > a[0][0]){//遍历的元素和第一个元素比较，谁大留谁值，再找后面的元素比较 max = a[i][j];}}}printf("a二维数组中最大的元素是：%d,%d行,%d列。",max,i,j); return 0;
}

9.大小写字母转换

#include <stdio.h>int main(int argc, char *argv[])
{ char ch1,ch2;printf("请输入您要转换的字符：");scanf("%c",&ch1);if(ch1 >= 65 && ch1 <= 90){ch2 = ch1 + 32; printf("%c",ch2);}if(ch1 >= 97 && ch1 <= 122){ch2 = ch1 - 32;printf("%c",ch2);}return 0;
}

10.打印平行四边形

#include <stdio.h>
int main()
{int line,i,j,k;printf("请输入边：\n");scanf("%d",&line); for(i = 0; i <= line;i++){for(k = 0; k <= i-1;k++){printf(" ");}for(j = 0; j <= line; j++){printf("*");}printf("\n");}return 0;}

11.字符串翻转

#include <string.h>
int main()
{char a[]  = "welcome to my world";char *p,*q;char t; p = NULL;q = NULL;p = a;q = a + strlen(a) - 1;while(p < q){t = *q;*q = *p;*p = t;p++;q--;}printf("%s\n",a);return 0;}

12.a++与++a，先从右到左运算，再从左到右赋值。a++先赋值再运算，++a先运算再赋值。

13.利用指针交换两个变量的值。

#include <stdio.h>
void swap(int *pa,int *pb);
int main()
{int a = 10,b = 30;swap(&a,&b);printf("a = %d b =%d ",a,b);return 0;}void swap(int *pa,int *pb)
{int t;t = *pa;*pa = *pb;*pb = t;}

14.用指针找出一个数组中最大和最小的元素。

#include <stdio.h>
void maxmin(int a[],int len,int *max,int *min);int main(void)
{int a[] = {1,2,3,4,5,6,89,661,1232,56,8820,234};int max,min;maxmin(a,sizeof(a)/sizeof(a[0]),&max,&min);printf("a数组中最大的是：%d，最小的为：%d",max,min); return 0;
}
void maxmin(int a[],int len,int *max,int *min)
{int i;*max  = *min =a[0]; for(i = 1; i < len;i++){if(*min > a[i]){*min = a[1];}if(*max < a[i]){*max = a[i];}}
}

15.代码实现strcpy和strcat

int main()
{int i = 0,j = 0;char a[50] = "hello";char b[50] = "world";while(a[i] != '\0'){i++;    }while(b[j] != '\0'){a[i] = b[j];j++;i++;}a[i] = '\0';printf("%s\n",a);
}

另外一种方法

#include <stdio.h>
void mystrcpy(char *p,char *q);int main()
{char a[50] = "hello";char b[50] = "world";mystrcpy(a,b);printf("%s",a);    return 0;
}
void mystrcpy(char *p,char *q)
{   while(*p !='\0'){p++;  }while(*q !='\0'){*p=*q;p++;q++; }*q ='\0';
}

int main()
{int i = 0,j = 0;char a[50] = "hello";char b[50] = "world";while(b[j] != '\0'){a[i] = b[j];j++;i++;}a[i] = '\0';printf("%s\n",a);
}

16 去掉一段字符串中的空格

#include <stdio.h>
int main()
{char a[50]  = {0};gets(a);char *p,*q;p = a,q = a;while(*q != '\0'){if(*q == ' '){q++;}else{*p =*q;p++;q++;}}*p = '\0';printf("a = %s\n",a);return 0;
}

17.函数封装strcat、strcpy

#include <stdio.h>
void mystrcat(char *str1,char *str2);
void mystrcpy(char *str1,char *str2);
int main()
{char a[50] = "asd";char b[20] = "fff";mystrcat(a,b);printf("%s\n",a);mystrcpy(a,b);printf("%s\n",a);return 0;
}   void mystrcat(char *str1,char *str2)
{char *p = str1;char *q = str2;while (*p != '\0'){p++;}while (*q != '\0'){*p = *q;p++;q++;}*p = '\0';
}   void mystrcpy(char *str1,char *str2)
{char *p = str1;char *q = str2;while (*q != '\0'){*p = *q;p++;q++;}*p = '\0';  }

18.函数封装字符串反转

#include <stdio.h>
#include <string.h>
char* str_swap(char *str);
int main()
{char str1[100] = {};scanf("%s",str1);str_swap(str1);puts(str1);return 0;
}char* str_swap(char *str)
{int len = strlen(str);char *p = str;char *q = str+len-1;char tmp;while(q > p){tmp = *q;*q = *p;*p = tmp;p++;q--;}
}

19.函数指针，封装四则运算。

#include <stdio.h>
int func(int a,int b,int(*p)(int a,int b));
int add(int a,int b);
int sub(int a,int b);
int div(int a,int b);
int mul(int a,int b);int main()
{int a = 12;int b = 3;int aet = cal(a,b,add);printf("ret = %d\n",aet);int set = cal(a,b,sub);printf("ret = %d\n",set);int det = cal(a,b,div);printf("ret = %d\n",det);int met = cal(a,b,mul);printf("ret = %d\n",met);return 0;
}       int cal(int a,int b,int (*p)(int ,int ))
{int ret;ret =(*p)(a,b);return ret;}int add(int a,int b){return a + b;}int sub(int a,int b){return a - b;}int div(int a,int b){return a / b;}int mul(int a,int b){return a * b; }

20.使用函数指针数组封装加减法

#include <stdio.h>
int sub(int a,int b);
int add(int a,int b);
int main()
{int a = 10;int b = 5;int (*p[2])(int a,int b) = {sub,add};int aet = (*p[0])(a,b);printf("sub  = %d\n",aet);int set = (*p[1])(a,b);printf("add  = %d\n",set);return 0;
}int sub(int a,int b)
{return a - b;
}
int add(int a,int b)
{return a + b;
}

21.函数封装完成输入一个数，实现阶乘的功能。

#include <stdio.h>
int func(int num);
int main()
{int num,i;int ret;printf("please inpur a numbers:\n");scanf("%d",&num);ret = func(num);printf("%d! = %d\n",num,ret);return 0;
}int func(int num)
{int ret = 1;int i;for(i = num; i > 0;i--){ ret  = ret * i;   } return ret;
}

22.递归实现阶乘

#include <stdio.h>
int main()
{printf("input a number:");int num;scanf("%d",&num);int sum = fac(num);printf("%d! = %d",num,sum);return 0;
}
int fac(int num)
{if(num == 0){return 1;}return num * fac(num - 1);
}

24.结构体练习

#include <stdio.h>
#include <string.h>struct birth
{int year;int month;int day;
};struct stu
{int age;char name[10];struct birth birthday;char sex[10];
};int main()
{struct stu stu1 = {18,"xiao mei",{1999,12,22},"man"};printf("%s\n",stu1.name);strcpy(stu1.name,"haha");printf("%s\n",stu1.name);printf("%d",stu1.birthday.year);return 0;
}

25.输入一个100 - 1000的数，判断该数是否为水仙花数。

#include <stdio.h>
int main()
{printf("please imput 100-1000:");int a;scanf("%d",&a);if(a >= 100 && a <= 1000){int g = a % 10;int s = a / 10 % 10;int b = a / 100;if(a == b*b*b +s*s*s +g*g*g ){printf("%d是水仙花数",a); }else{printf("%d不是水仙花数",a);}}else{printf("error input ");}  return 0;
}

26.输入一个数，数组按该数进行移动，并且打印。

#include <stdio.h>
int main()
{int a[10] = {1,2,3,4,5,6,7,8,9,10};int *p = a;int *q = a;printf("请输入要移动的位数：");int m;scanf("%d",&m);int k = 0;for(k = 0;k < 10;k++){printf("%d",p[k]);}puts(" ");int i = 0;for(i = 10 - m; i < 10;i++){printf("%d",*(p+i));}int j = 0;for(j = 0;j < 10 - m;j++){*(p+j) = *(q+j);printf("%d",*(p+j));}}

27.将下列按照国家名字排序 china japan italy frech egland

#include <stdio.h>
int main()
{char *a[]= {"china","japan","italy","frech","eglang"};char *tmp = NULL;int i = 0,j = 0;printf("before：\n");for(i = 0;i < 5;i++){printf("%s ",a[i]);}for(j = 0;j < 4;j++){for(i = 0;i < 4;i++){if(*a[i] > *a[i+1]){tmp = a[i+1];a[i+1]=a[i];a[i]=tmp;   }}}puts(" ");printf("after：\n");for(i = 0;i < 5;i++){printf("%s ",a[i]);}return 0;
}

28.随机输入10个整数，将他们按从小到大排序

#include <stdio.h>
int main()
{int i = 0;int j = 0;int a[10] = {};printf("请随机输入十个整数：\n");printf("排序前：\n");for(i = 0;i < 10;i++){scanf("%d",&a[i]);}  for(j = 0;j < 9;j++){for(i = 0; i < 9;i++)//比较大小 ，将大的数移到最后面。 {if(a[i] > a[i+1]){int tmp;tmp = a[i+1];a[i+1] = a[i];a[i] = tmp;}     }   }printf("排序后：\n");for(i = 0;i < 10;i++){printf("% d",a[i]);}return 0;
}

29.求阶乘的和。

#include <stdio.h>
int mul(int n);
int addmul(int n);
int main()
{int n= 0;printf("请输入要求的阶乘的和：\n");scanf("%d",&n);printf("%d! = %d",n,addmul(n));return 0;
}
int mul(int n)
{if(n == 0){return 1;}if(n > 0){int sum = 0;return n*mul(n - 1);}
}
int addmul(int n)
{if(n > 0){return mul(n)+addmul(n-1);}
}

30.输入一个年月日求该日是该年的第几天。

#include <stdio.h>
struct data
{int year;int month;int day;
}data;int main()
{int a,i,sum,j,sum1; printf("请输入年月日：");scanf("%d%d%d",&data.year,&data.month,&data.day);if(data.year%400==0)a=1;else{if(data.year%4==0&&data.year%100!=0)a=1;elsea=0;}if(a==1){printf("%d 此年是闰年\n",data.year);int b[12] = {31,29,31,30,31,30,31,31,30,31,30,31};for(i = 0;i<(data.month)-1;i++){sum +=b[i];}    printf("%d月%d日是该年的第%d天\n",data.month,data.day,sum+data.day);} else{printf("%d 此年非闰年\n",data.year);int b[12] = {31,28,31,30,31,30,31,31,30,31,30,31};for(j = 0;j<(data.month)-1;j++){sum1 +=b[j];}     printf("%d月%d日是该年的第%d天\n",data.month,data.day,sum1+data.day);}   return 0;
}

31.将输入的数据保存在开辟地址空间里，再遍历出来。

#include <stdio.h>
#include <stdlib.h>
int main()
{int a[10] = {};int i=0,j = 0;for(i = 0;i <10 ;i++){scanf("%d",&a[i]);}int* p=(int*)malloc(10*sizeof(int));if(NULL == p){printf("create defualt\n");}else{printf("create success\n")  ;}for(j = 0;j <10 ;j++){printf("%d",p[i] =a[j]);}free(p);p = NULL;return 0;
}

32. 有一个游戏，取一个花色的所有13张扑克牌，成为一摞，按照如下的规则取牌：
（1）将最上面一张牌放到这一摞牌的最下面
（2）然后将最上面的一张牌取出
以后不断重复1,2的动作，直到所有的扑克牌取完为止。
问题：如果要使得取出扑克牌的顺序为从小到大，即顺序为：A、2、3、4、5、6、7、8、9、10、J、Q、K，请使用C/C++编程求出最初扑克牌的顺序应该是什么。

#include <stdio.h>
int main()
{char a[14]= "A23456789UJQK";char b[14] = {0};int i,j;for(i=0,j=1;j<13;i++,j+=2)//第一次遍历完整个数组。 {b[j]=a[i];}for(i=6,j=0;j<=13;i++,j+=4)// {b[j]=a[i];}for(i=11,j=2;j<13;i++,j+=8){b[j]=a[i];}b[6]=a[10];for(i=0;i<13;i++){putchar(b[i]);}puts("");return 0;}

33.猜数字游戏。系统随机生成一个随机数，去猜这个随机数，每次猜未猜中报猜大了还是猜小了，猜中了就退出，并且记录猜的的次数。

#include <iostream>
#include <ctime>
using namespace std;
int main()
{int num = 0;srand((unsigned int)time(NULL));num = rand() % 100 + 1;cout << num << endl;int your_num = 0;int count = 0;while (1){cout << "please input your numbers:" << endl;count++;cin >> your_num;if (your_num == num){cout << "您猜对啦,num = " <<num << endl;cout << "您一共猜了 " << count<<"次"<< endl;break;}if (your_num > num){cout << "您猜大啦，猜小一点 " << endl;}if (your_num < num){cout << "您猜小啦，猜大一点 " << endl;}}return 0;
}

34.9*9乘法表

#include <iostream>
using namespace std;
int main()
{int i, j;for (i = 1; i <= 9; i++)//控制行数{for (j = 1; j <= i; j++)//控制列数{cout << i << "*" << j << "=" << i * j << "\t";}cout << endl;     }return 0;
}

35.找出数组里的最大值

#include <iostream>
using namespace std;
int main()
{int a[6] = { 300,400,800,600,700 ,900};int max = 0;for (int i = 0; i < sizeof(a)/sizeof(a[0]); i++){//if (a[i] > max)//{//  max = a[i];//}max = a[i] > max ? a[i] : max;}cout << max << endl;return 0;
}

36.数组里的元素的互换

#include <iostream>
using namespace std;
int main()
{int a[6] = { 300,400,800,600,700 ,900 };int start = 0;//开始时元素的下标int end = sizeof(a) / sizeof(a[0]) - 1;// 末尾元素的下标for (int i = 0; i < sizeof(a) / sizeof(a[0]); i++){cout << a[i]<<" ";}cout << endl;while (start < end)//start<end 时才执行互换，当大于或者等于时停止交换。{int temp = 0;temp = a[start];a[start] = a[end];a[end] = temp;//完成换位置end--;start++;}for (int i = 0; i < sizeof(a) / sizeof(a[0]); i++){cout << a[i] << " " ;}return 0;
}

37.冒泡排序c++

#include <iostream>
using namespace std;
int main()
{int a[9]= { 32,44,556,676,342,745,855,24,7567 };for (int i = 0; i < sizeof(a) / sizeof(a[0]); i++){cout << a[i] << " ";}cout << endl;for (int  j = 0 ; j < (sizeof(a) / sizeof(a[0])-1); j++)//重复9次{for (int i = 0; i < (sizeof(a) / sizeof(a[0])-j-1); i++){int temp = 0;if (a[i] > a[i + 1])//比较相邻的两数，把大的放在后面。{temp = a[i];a[i] = a[i + 1];a[i + 1] = temp;}}}for (int i = 0; i < sizeof(a) / sizeof(a[0]); i++){cout << a[i] << " ";}return 0;
}

38.看代码

#include <iostream>
#include <string>
#include <ctime>
using namespace std;
struct student {string sName;int score;};
struct teacher
{string tName;struct student sArry[5];
};
void allocateSpace(struct teacher tArry[],int len);
void printInfo(struct teacher tArry[], int len);
int main()
{    //随机srand((unsigned int)time(NULL));//1.创建3位老师的数组struct teacher tArry[3];//2.通过函数给3位老师和5位学生的信息赋值int len = sizeof(tArry) / sizeof(tArry[0]);allocateSpace(tArry, len);printInfo(tArry, len);//3.打印return 0;
}
void allocateSpace(struct teacher tArry[],int len)
{string nameSeed = "ABCDE";for (int i = 0; i < len; i++){tArry[i].tName = "teacher_";tArry[i].tName += nameSeed[i];//通过循环给每位老师所带的学生赋值for (int j = 0; j < 5; j++){tArry[i].sArry[j].sName = "student_t";tArry[i].sArry[j].sName += nameSeed[j];int random =  rand() % 61 + 40;tArry[i].sArry[j].score = random;}}
}
void printInfo(struct teacher tArry[], int len)
{for (int i = 0; i < len; i++){cout << "老师姓名" << tArry[i].tName << endl;for (int j = 0; j < 5; j++){cout << "\t"<<"学生姓名" << tArry[i].sArry[j].sName <<"考试分数:" << tArry[i].sArry[j].score << endl;}}}

39.结构体数组按成绩年纪排升序

#include <iostream>
#include <string>
#include <ctime>
using namespace std;
struct hero
{string name;int age;string sex;};
//冒泡排序实现年纪的升序
void bubbleSort(struct hero heroArry[], int len);
void printSort(struct hero heroArry[],int len);
int main()
{hero heroArry[5] = {{"刘备",23,"男"},{"关羽",22,"男"},{"张飞",20,"男"},{"赵云",21,"男"},{"貂蝉",19,"女"}};int len = sizeof(heroArry) / sizeof(heroArry[0]);printSort(heroArry, 5);cout << "排序之后" << endl;bubbleSort(heroArry, 5);printSort(heroArry, 5);return 0;
}
void bubbleSort(struct hero heroArry[], int len)
{for (int i = 0; i < len - 1; i++){for (int j = 0; j < len - i - 1; j++){if (heroArry[j].age < heroArry[j + 1].age){struct hero temp = heroArry[j];heroArry[j] = heroArry[j + 1];heroArry[j + 1] = temp;}}}}void printSort(struct hero heroArry[], int len)
{for (int i = 0; i < len; i++){cout << "姓名： " << heroArry[i].name <<" "<< "年纪： " << heroArry[i].age <<" "<< "性别： " << heroArry[i].sex << endl;}
}