C语言编程3道题

1,
#include
int nixu(int n){
int a,= 0,b = 1000;
do{
a += b*(n%10);
b /= 10;
}while(n/10);
return a;
}
int main(){
int i = 0,j = 1000;
scanf("%d",&i);
for(;j < 10000;i++){
if(nixu(j) == j *n)
printf("%d",j);
return 0;
}
}
2,
#include
int main(){
int age[20],d[11] = {0},i = 0;
scanf("%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d",&age[0],
&age[1],&age[2],&age[3],&age[4],&age[5],&age[6],&age[7],&age[8],&age[9],
&age[10],&age[11],&age[12],&age[13],&age[14],&age[15],&age[16],&age[17],
&age[18],&age[19]);
for(i = 0;i < 20;i ++){
if(age[i] < 10)
d[0]++;
else if(age[i] < 20)
d[1]++;
else if(age[i] < 30)
d[2]++;
else if(age[i] < 40)
d[3]++;
else if(age[i] < 50)
d[4]++;
else if(age[i] < 60)
d[5]++;
else if(age[i] < 70)
d[6]++;
else if(age[i] < 80)
d[7]++;
else if(age[i] < 90)
d[8]++;
else if(age[i] < 100)
d[9]++;
else d[10] ++;
}
for(i = 0;i < 11;i ++)
printf("%d ",d[i]);
return 0;
}
3,
#include
int main(){
int a,b,c,i;
scanf("%d%d%d",&a,&b,&c,);
for(i = ((a if(!(a%i||b%i||c%i)){
printf("%d",i);
return 0;
}
}

#include
int countdigit(int number,int digit)
{
int count=0;
while(number!=0)
{
if(number%10==digit)count++;
number/=10;
}
return count;
}
main()
{
int number,digit;
scanf("%d%d",&number,&digit);
printf("%d\n",countdigit(number,digit));
}