分类： C/C++
2014-01-10 09:31:34
题目1：八进制转换为十进制
#include
int main(void)
{
char *p,s[6];
int n = 0;
p = s;
gets(p);
while(*(p)!='\0') //'0'的ascll码值是48，*p是字符型
{
n = n*8+*p-'\0';
p++;
}
printf("%d\n",n);
return 0;
}
题目2：两个字符串连接程序
#include
int main(void)
{
char a[10],b[10],c[20];
int i=0,j=0,k=0;
gets(a);
gets(b);
while(a[i]!='\0')
{
c[k]=a[i];
i++;
k++;
}
while(b[j]!='\0')
{
c[k]=b[j];
j++;
k++;
}
c[k]='\0'; //最后加上字符串结束符
printf("%s\n",c);
//puts(c);
return 0;
}
题目3：结构体变量传递程序
include "stdio.h"
struct student
{
int x;
char c;
}a;
void f1(struct student b);
void f2(struct student* b);
void main(void)
{
a.x=3;
a.c='a';
f1(a);
printf("%d,%c\n", a.x, a.c); // 3 ‘a’ 结构体变量作形参时，其成员的值不会变
f2(&a);
printf("%d,%c\n", a.x, a.c); // 20 ‘y’ 结构体变量的地址作形参时，其成员的值会变
}
void f1(struct student b)
{
b.x=20;
b.c='y';
}
void f2(struct student* b)
{
b->x = 20;
b->c = 'y';
}
题目4：某公司采用公用电话传递数据，数据是四位的整数，在传递过程中是加密的，规则如下： 每位数字都加上5,然后用除以10的余数代替该数字，再将第一位和第四位交换，第二位和第三位交换。
#include "stdio.h"
int main(void)
{
int n,i,t;
int a[4];
scanf("%d",&n);
a[0] = n%10;
a[1] = n%100/10;
a[2] = n%1000/100;
a[3] = n/1000;
for(i=0;i<=3;i++)
{
a[i] = a[i]+5;
a[i] = a[i]%10;
}
for(i=0;i<=3/2;i++)
{
t = a[i];
a[i] = a[3-i];
a[3-i] = t;
}
for(i=3;i>=0;i--)
{
printf("%d",a[i]);
}
return 0;
}
题目5：按位与，或，异或，同或
#include "stdio.h"
int main(void)
{
int a,b,c,d,e;
int i,j;
i = 0xff;
j = 0xfe;
a = i&j;
b = i|j;
c = i^j;
d = !i^j;
e = ~j; //-255 1111 1110取反后0000 0001
-255的表示方法是0000 0000取反加1，即0000 0001
printf("%d %d %d %d %d\n",a,b,c,d,e);
return 0;
}
题目6：有1、2、3、4个数字，能组成多少个互不相同且无重复数字的三位数？都是多少？
#include "stdio.h"
int main(void)
{
int i,j,k,n;
n=0;
for(i=1;i<5;i++)
{
for(j=1;j<5;j++)
{
for(k=1;k<5;k++)
{
if((i!=j)&&(i!=k)&&(j!=k))
{
printf("%d%d%d\n",i,j,k);
n++;
}
}
}
}
printf("%d",n);
return 0;
}
题目7：一个整数，它加上100后是一个完全平方数，再加上168又是一个完全平方数，请问该数是多少？
#include "stdio.h"
#include "math.h"
int main(void)
{
long int i,x,y;
for(i=0;i<10000;i++)
{
x = sqrt(i+100);
y = sqrt(i+268);
if((x*x==i+100)&&(y*y==i+268))
printf("%ld\n",i);
}
return 0;
}
题目8：输入某年某月某日，判断这一天是这一年的第几天？
#include "stdio.h"
int main(void)
{
int year,mon,day;
int leap,sum;
scanf("%d %d %d",&year,&mon,&day);
switch(mon)
{
case 1:sum=0;break;
case 2:sum=31;break;
case 3:sum=59;break;
case 4:sum=90;break;
case 5:sum=120;break;
case 6:sum=151;break;
case 7:sum=181;break;
case 8:sum=212;break;
case 9:sum=243;break;
case 10:sum=273;break;
case 11:sum=304;break;
case 12:sum=334;break;
default :printf("data error");break;
}
sum = sum+day;
if(year%4 == 0)
leap=1;
else
leap=0;
if(leap==1) sum = sum+1;
printf("It is the %d th day",sum);
return 0;
}
题目9：该程序读取输入直到遇到#字符，然后报告空格数目，换行符数目。
#include "stdio.h"
int main(void)
{
char c;
int i,j;
i=0;
j=0;
while((c=getchar())!='#')
{
if(c==' ')
i++;
if(c=='\n')
j++;
}
printf("the end\n");
printf("spaces:%d newlines:%d\n",i,j);
return 0;
}
题目10：指向指针的指针
#include "stdio.h"
int main(void)
{
char *s[]={"man","woman","baby"};
char **q;
int k;
for(k=0;k<3;k++)
{
q=&(s[k]);
printf("%s\n",*q);
}
return 0;
}
题目11：输入四个同学的分数，最后打印出他们的分数，分数平均值和每一科的平均值
#include
#include
#define LEN 14
#define CSIZE 4
#define SCORES 3
struct name {
char
first[LEN];
char
last[LEN];
};
struct student {
struct
name person;
float
scores[SCORES];
float
mean;
};
void get_scores(struct student al[],int
lim);
void find_means(struct student al[],int
lim);
void show_class(const struct student ar[],
int lim);
void show_ave (const struct student ar[],
int lim);
int main()
{
struct
student classes[CSIZE] = {
{"File","Snide"},
{"Clare","Voyans"},
{"Bingo","Higgs"},
{"Fawn","Hunter"}
};
get_scores(classes,CSIZE);
find_means(classes,CSIZE);
show_class(classes,CSIZE);
show_ave
(classes,CSIZE);
return
0;
}
void get_scores(struct student al[],int
lim)
{
int
i,j;
for(i=0;i
{
printf("please
enter %d scores for %s
%s:\n",SCORES,al[i].person.first,al[i].person.last);
for(j=0;j
{
while(scanf("%f",&al[i].scores[j])
!= 1)// 非1时表示输入与类型不符合
{
scanf("%*s");//跳至下一空白字符，不把此数据读入
puts("Please
use numeric input");
}
}
}
}
void find_means(struct student al[],int
lim)
{
int
i,j;
float
sum;
for(i=0;i
{
for(sum=0,j=0;j
sum
= sum+al[i].scores[j];
al[i].mean
= sum / SCORES;
}
}
void show_class(const struct student ar[],
int lim)
{
int
i, j;
char
wholename[2*LEN];
for
(i = 0; i < lim; i++)
{
strcpy(wholename,
ar[i].person.first);//复制字符串函数
strcat(wholename,
" ");//字符串连接函数，先去掉结束符，连接后再加上结束符
strcat(wholename,
ar[i].person.last);
printf("%27s:
", wholename); //输出27位
for
(j = 0; j < SCORES; j++)
printf("%6.1f
", ar[i].scores[j]);
printf("
Average = %5.2f\n", ar[i].mean);
}
}
void show_ave (const struct student ar[],
int lim)
{
int
i, j;
float
total;
printf("\n%27s:
", "QUIZ AVERAGES");
for
(j = 0; j < SCORES; j++)
{
for
(total = 0, i = 0; i < lim; i++)
total
+= ar[i].scores[j];
printf("%6.2f
", total / lim);
}
putchar('\n');
}
题目12：用指向函数的指针数组执行菜单
#include
#define NUM 4
double twice(double x);
double half(double x);
double thrice(double x);
void showmenu(void);
int main()
{
double
(*pf[NUM])(double) = {twice,half,thrice}; //声明指向函数的指针数组
double
val,ans;
int
sel;
printf("enter
a number:");
while(scanf("%lf",&val)&&val>0)
{
showmenu();
while(scanf("%d",&sel)&&sel>=0&&sel<3)
{
ans
= (*pf[sel])(val);
printf("answer
= %f\n",ans);
showmenu();
}
printf("enter
next number:");
}
return
0;
}
void showmenu()
{
printf("enter
one of the following choices:\n");
puts("0)
double the value\n");
puts("1)
halve the value\n");
puts("2)
triple the value\n");
}
double twice(double x) {return 2.0 * x;}
double half(double x) {return x / 2.0;};
double thrice(double x) {return 3.0 * x;}
