Bài tập C intro 1 ->8

#include<stdio.h>

void main()

{

    int a,b=0;

    printf("nhap cac so thuc:");

    do

    {

        scanf("%d",&a);

        if(a%5==0) b= a<b ? b:a;

    }while(a!=0);

    printf("So chi het cho 5 lon nhat duoc nhap:%d",b);

}

#include<stdio.h>

void main()

{

    int i,a,x,s[12];

    char so[10][6]={"khong","mot","hai","ba","bon","nam","sau","bay","tam","chin"};

    char hang[2][6]={"muoi","tram"};

    char doc[4][6]={"","nghin","trieu","ti"};

    printf("nhap so a:");

    scanf("%d",&a);

    x=a;

    i=0;

    do

    {

        s[i]=x%10;

        x=x/10;

        i++;

    }while(x!=0);

    x=i;

    printf("doc so:");

    a=1;

    for(i=x-1;i>=0;i--)

    {

        if(i%3==2)if(s[i]!=0) printf(" %s %s",so[s[i]],hang[1]);

        if(i%3==1)

        {

            if(s[i]!=0&&s[i]!=1) printf(" %s %s",so[s[i]],hang[0]);

            if(s[i]==1) printf(" %s",hang[0]);

        }

        if(i%3==0)

        {

            if(s[i]!=0) printf(" %s",so[s[i]]);

            if(a) printf(" %s",doc[i/3]);

            if(s[i]==0) a=0;

        }

    }

    printf(" dong");

}

#include<stdio.h>

main()

{

    int c;

    int cach=0;

    while((c=getchar()!=EOF))

            putchar(c);

    {

        if(c==' ')

        {

         if(c==' ')

         {

             if(cach==0)

             {

                 cach=1;

                 putchar(c);

             }

         }

         if(c!=' ')

         {

             cach=0;

             putchar(c);

         }

        }

    }

    return 0;

}