2022-01-24 포인터 연습

---

/*

#include <stdio.h>
int main()
{
    char str[] = "World Computer";
    char* ptr = str + 0;

    printf(" [ %c ] \n", *ptr + 5);
    printf(" [ %s ] \n", ptr + 1);
    p = p + 2;
    printf(" [ %c ] \n", *p );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    char language[] = "visual c++";
    char* ptr = language;
    ptr++;
    ++ptr;
    printf(" [ %c ] \n", (*ptr)++ );
    printf(" [ %s ] \n",  ptr );
    printf(" [ %s ] \n", ++ptr );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    char* language[] = {"visual c++", "java", "basic", "delphi"};
    char** ptr = language;

    printf("[ %c ] \n",  *language[3] );
    printf("[ %d ] \n",  *language);
    printf("[ %s ] \n",  *++ptr);

    return 0;
}
*/
/*
#include <stdio.h>

int main()

{
    int x = 10;
    int* p;
    p = &x;

    printf( "%d\n", x );
    printf( "%d\n", *p++ );
    printf( "%d\n", x );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int x = 10, y = 20;
    int  *p, *q;

    p = &x;
    q = &y;

    printf("%d\n", ++*p + (*q)++ );
    printf("%d %d\n",  x,  y++ );
    printf("%d %d\n" , *p , *q  );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int ar[5] = {1, 2, 3, 4, 5};
    int* p = ar;

    printf("%d\n", ar);
    printf("%d\n", p );
    printf("%d\n", *p );
    printf("%d\n", ar[0] );
    printf("%d\n", p[0] );

    return 0;
}

*/
/*
#include <stdio.h>

int main()
{
    int ar[] = {2, 7, 1, 5, 3};
    int* p = ar;

    printf("%d ", p[1] );
    printf("%d ",*p  );
    printf("%d ",*(p + 4)  );
    printf("%d ",*++p  );


    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    char str[] = "World Computer!!";
    char* p = str;

    printf("%c \n" , *(p + 6) );
    printf("%c \n" , p[0] );
    printf("%s \n" ,  p + 6 );
    printf("%s \n" , str + 14 );

    return 0;
}

*/
/*
#include <stdio.h>

int main()
{
    int ar[] = {2, 7, 1, 5, 3};
    int* p = ar;
    int* pp = ar + 4;

    printf("%d", *p );
    printf("%d", *pp );


    return 0;
}
*/
/*
#include <stdio.h>

void add(int* x)
{
    *x = 100;
    printf("%d\n", *x );

    return 0;
}

int main()
{
    int x;
    x = 2;
    printf("%d\n", x );
    add(&x);
    printf("%d\n", x );

    return 0;
}
*/
/*
#include <stdio.h>

void func(int* x)
{
    x[0] = 10;
}

int main()
{
    int ar[5] = {1, 2 ,3 ,4 ,5 };
    printf("%d\n", ar[0] );
    func(ar);
    printf("%d\n", ar[0] );

    return 0;
}
*/
/*
#include <stdio.h>

void swap(int a, int b)
{
    int t;
    t = a;
    a = b;
    b = t;

}


int main()
{
        int x, y;
        x = 2, y = 3;
        printf("%d %d\n", x, y );
        swap(x, y);
        printf("%d %d\n", x, y );



    return 0;
}

*/
/*
#include <stdio.h>

void swap(int* a, int* b)
{
    int t;

    t = *a;
    *a = *b;
    *b = t;
}

int main()
{
    int x = 2, y = 3;

    printf("%d %d\n", x,  y );

    swap( &x, &y );

    printf("%d %d", x, y );


    return 0;
}
*/
/*

#include <stdio.h>

void myswap(int* x, int* y)
{
    int t;

    if( x > y )
    {
         t = *x;
        *x = *y;
        *y = t;
    }
}

int main()
{
    int a, b;
    scanf("%d %d", &a, &b );
    myswap(&a, &b);
    printf("%d %d", a, b);

    return 0;

}
*/
/*
#include <stdio.h>

int main()
{
    int x = 10;
    int* p = &x;
    int** pp = &p;

    printf("%d\n", x );
    printf("%d\n", *p );
    printf("%d\n", **pp );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int x = 10;
    int* p = &x;
    int** pp = &p;

    printf("%d\n", x );
    printf("%d\n", *p );
    printf("%d\n", **pp );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int x = 10;
    int* p = &x;
    int** pp = &p;
    int*** ppp = &pp;

    x = 100;

    printf("%d\n", *p );
    printf("%d\n", **pp );
    printf("%d\n", ***ppp );

    return 0;
}


*/
/*
#include <stdio.h>

void f()
{
    printf("hello");
}

int main()
{
    void (*p)();
    p = f;
    p();

    return 0;
}
*/
/*
#include <stdio.h>

void f(int a, int b)
{
    int i, s = 1;
    for(i = 1;i <= b; ++i)
    {
        s = s * a ;
        printf("%d", s);
    }
}

int main()
{
    void (*fp)(int, int);
    fp = f;
    fp(2, 5);

    return 0;
}

*/
/*
#include <stdio.h>

int f1(int a)
{
    return a * a;
}

double f2(int a, int b)
{
    return ( a + b ) / 2.0;
}

int main()
{
   int (*fp)(int);

   double( *dp)(int, int);
    fp = f1;
    dp = f2;

    printf("%.2lf", dp( fp(3), fp(4) )  );

    return 0;
}
*/
/*
#include <stdio.h>

int f(int* a)
{
    int i , s = 0;
    for( i = 0; i < 5; ++i)
    {
        s += a[i];
    }
    return s;
}



int main()
{
    int a[] = {4, 7, 1, 5, 3};
    int k = f(a);

    printf("%d", k );

    return 0;
}

*/
/*
#include <stdio.h>

int f(int* a)
{
    int i, s = 0;

    for(i = 0; i < 5; ++i)
    {
        s += a[i];
    }

    return s;
}



int main()
{
    int a[] = { 4, 7, 1, 5, 3};

    int k = f(a);

    printf("%d", k);

}
*/
/*
#include <stdio.h>

int f(int* a)
{
    int i, s = 0;
    for(i = 0;i < 5; ++i)
    {
        s = s + *(a + i);
    }
    return s;
}

int main()
{
    int a[] = {4, 7, 1, 5, 3};
    int k = f(a);
    printf("%d", k);
    return 0;
}
*/
/*
#include <stdio.h>

void rever(char* a)

{
    int i;
    for(i = 0; a[i] ; ++i)
    {
        putchar(a[i]);
    }
}

int main()
{
    char  str[] = "World Computer";

    rever(str);

    return 0;
}

*/
/*
#include <stdio.h>

int mlen(char* a)
{
    int i, k = 0;

    for(i = 0; a[i]; ++i) k++;

    return k;
}

int main()
{
    char str[] = "World Computer";
    int k = mlen(str);
    printf("%d", k);

    return 0;
}
*/
/*
#include <stdio.h>

void sayhello(void)
{
    printf("Hello, World!");

    return;
}


int main()
{
    void (*pf)(void);
    pf = sayhello;
    pf();

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int x = 10, y = 20;
    int* p, *q;

    p = &x;
    q = &y;

    printf("%d\n", ++*p  + (*q)++);
    printf("%d %d\n", x , y++ );
    printf("%d %d\n",*p ,*q);


}
*/
/*
#include <stdio.h>

int main()
{
    int number  = 100;
    int arr[4] = {10, 0, 20, 50};
    char data = 'A';

    int* pNumber = &number;
    int* pArr = &arr[2];
    char* pData = &data;
    double* pDouble;
    *pNumber = 50;

    printf("(1) %d \n", sizeof(pArr));
    printf("(2) %d \n", sizeof(pData));
    printf("(3) %d \n", sizeof(pDouble));
    printf("(4) %d \n", number  );
    printf("(5) %d \n", *pNumber);
    printf("(6) %d \n", arr[3] - arr[1] );
    printf("(7) %d \n", &arr[3] - &arr[1]);
    printf("(8) %d \n", ('B' - *pData) * 10 );


    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int data[4][2] = { 1, 2, 3, 4, 5, 6, 7, 8};
    int(* p)[2] = data;

    printf("(1) %d %d\n", data,  data[0]);
    printf("(2) %d %d\n", p,  p + 1);
    printf("(3) %d ", sizeof(p) );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int data[4][2] = {1, 2, 3, 4, 5, 6, 7, 8};
    int(* p)[2] = data;

    printf("(1) %d %d\n",  *(*(p+2)+ 1),  *(*(p) + 1)  );
    printf("(2) %d %d", data[0][0], p[0][0]  );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    int com[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
    int *p = com + 1;
    ++p;

    printf(" [ %d ] \n", *p );
    printf(" [ %d ] \n", *(p++) );
    printf(" [ %d ] \n", *p );
    printf(" [ %d ] \n", ++*p++ );


    return 0;
}
*/
/*
#include <stdio.h>

int main(void)
{
    char* a = "computer  science";
    int len = 0, i;

    printf("(1) %c \n", *a + 1 );
    printf("(1) %c \n", *(a + 2) );
    printf("(1) %s \n", a + 3 );

    for(i = 0;i < 100; ++i)
    {
        if ( *(a + i) == '\0'  ) break;
        ++len;

    }
    printf("(4) -------\n");

    for(i = len - 1; i >= 0; --i)
    {
        if ( *(a + i) == 'e' )
        {
            printf("%s \n", a + i);
        }

    }
    return 0;
}

*/
/*
#include <stdio.h>

int main()
{
    int p;
    char str[] = "World computer";
    char* ptr = str + 0;

    printf(" [ %c ] \n", *ptr + 5 );
    printf(" [ %s ] \n", ptr + 1 );
    p = ptr + 2;

    printf(" [ %c ] \n", *p );

    return 0;
}
*/
/*
#include <stdio.h>

int main()
{
    char language[] = "visual c++";
    char* ptr = language;

    ptr++;
    ++ptr;

    printf("[ %c ] \n", *(ptr)++ );
    printf("[ %s ] \n", ptr );
    printf("[ %s ] \n", ++ptr );

    return 0;
}

*/
/*
#include <stdio.h>

int main()
{
    char* language[]= { "visual c++", "java", "basic", "delphi" };
    char** ptr =  language;

    printf("[ %c ] \n", *language[3] );
    printf("[ %s ] \n", *language );
    printf("[ %s ] \n", *++ptr );

    return 0;
}
*/
/*
#include <stdio.h>

void f(int a, int b)
{
    int i, s = 1;
    for(i = 1;i <= b; ++i)
    {
        s = s* a;
        printf("%d", s);
    }
}


int main()
{
    void (*fp)(int, int);

    fp = f;
    fp(2, 5);

     return 0;
}


*/
/*
#include <stdio.h>

int main()
{
    int a = 1, i = 0;

    for(i = 1;i <= 5; ++i)
    {
        printf("%d\n", a);
    }
    printf("%d\n", i);

    return 0;
}

*/
/*
#include <stdio.h>

void func()
{
    static int a = 0;
    printf("%d", a++);
}

int main()
{

    func();
    func();

    return 0;
}

*/
/*
#include <stdio.h>

void sfunc()
{
    static int a = 0;

    printf("%d", a++);

}
void func()
{
    int a = 0;
    printf("%d" , a++);
}

int main()
{
    int i;
    for(i = 1;i <= 3; ++i)
    {
        func();
    }
    printf("\n");

    for(i = 1;i <= 3; ++i)
    {
        sfunc();

    }
    return 0;
}
*/
/*
#include <stdio.h>

int a;

void func()
{
    printf("%d", a++);

}

int main()
{
    func();
    printf("%d\n", a);

    return 0;
}
*/
/*
#include <stdio.h>

int a;

void func1()
{

    printf("%d", ++a);
}

void func2()
{

    printf("%d", --a);
}

int main()
{
    int i;
    for(i = 1;i <= 3; ++i)
    {
        func1();
    }
    printf("\n");
     for(i = 1;i <= 3; ++i)
    {
        func2();
    }


    return 0;
}

*/
/*
#include <stdio.h>

void abs(float x)
{

    if( x > 0 )
    {
        printf("%.10g", x);
    }
    else
    {
        printf("%.10g", -x );
    }
    return;
}

int main()
{
   float n;

   scanf("%f", &n );

   abs(n);

    return 0;
}
*/
/*
#include <stdio.h>

float circle(int r)
{
    return (float) r * r * 3.14;
}

int main()
{
    int r;
    scanf("%d", &r );
    printf("%.2f", circle(r) );

}
*/
/*
#include <stdio.h>

int mymin(int a, int b)
{
    if( a < b)
    {
       return a;
    }
    else if( a > b)
    {
       return b;
    }

}

int main()
{
    int a, b;
    scanf("%d %d", &a, &b );
    printf("%d", mymin(a, b) );

    return 0;
}

*/
/*
#include <stdio.h>

int mymax(int x, int y)
{
    if ( x > y)
    {
        return x;
    }
    else if ( x <  y)
    {
        return y;
    }
}

int main()
{
    int a,  b;
    scanf("%d %d", &a, &b );
    printf("%d", mymax(a, b) );

    return 0;
}
*/
/*
#include <stdio.h>

int myabs(int x)
{
    if( x < 0 ) return -x;
    else return x;
}

int main()
{
    int a;
    scanf("%d", &a );
    printf( "%d", myabs(a) );

    return 0;
}
*/
/*
#include <stdio.h>

void f(void)
{
    printf("Hello?");

}

int main()
{
    f();
    return 0;
}

*/
/*
#include <stdio.h>

int n, k, d[1010];


{
   if( d[i] > k )
    {
        return i;
    }

    return 0;
}

int main()
{
    int i;

    scanf("%d", &n );

    for(i = 1; i <= n; ++i)
    {
        scanf("%d", &d[i]);
    }
    scanf("%d", &k );

    printf("%d\n", upper_bound(k) );

    return 0;
}

*/
/*
#include <stdio.h>

int i, n, k, d[1010]

int main()
{
    scanf("%d", &n );
    for( i = 1; i <= n; ++i)
    {
        scanf("%d", &d[i] );
    }
    scanf("%d", &k);
    printf("%d\n", findi(k) );

    return 0;
}

*/
/*
#include <stdio.h>

int n, a, b, d[1010];

long long int subsetsum( int a, int b )
{
    long long int i,  sum = 0;

    for( i =  a; i <=  b; ++i)
    {
        sum =  ( long long int ) sum + d[i];
    }
    return sum;
}


int main()
{
    int i;
    scanf("%d", &n );

    for(i = 1; i <= n; ++i)
    {
        scanf("%d", &d[i] );
    }
    scanf("%d %d", &a, &b );

    printf("%lld\n", (long long int) subsetsum(a, b) );

    return 0;
}
*/
/*
#include <stdio.h>

int a, n;

long long int pow(int x, int y)
{
    long long int cnt = 1;
    int i;

    for (i = 1;i <= y; ++i)
    {
        cnt = cnt * x;
    }

    return cnt;
}

int main()
{
    scanf("%d %d", &a, &n );

    printf("%lld\n", pow(a, n) );

    return 0;
}

*/
/*

#include <stdio.h>

int gcd(int p, int q)
{
    if(p == 0)
    {
        return q;
    }
}

int main()
{
    int a, b;
    scanf("%d%d", &a, &b );
    printf("%lld", lcm(a, b) );

    return 0;
}

*/
/*
#include <stdio.h>

int n;

long long int f(n)
{
    int i;
    long long int cnt = 0;

    for(i = 1; i <= n;++i)
    {
        cnt = cnt + i;
    }
    return cnt;
}

int main()
{
  scanf("%d", &n);
  printf("%lld\n", f(n));

}

*/

#include <stdio.h>
#include <string.h>

long long int n;

long long int f(n)
{
    int str[33];

    int i, cnt = 0;

    for( i = 1; i <= strlen(n)- 1; ++i )
    {
        n  = n / 10;
        cnt = cnt + n;
    }


}

int main()
{
    scanf("%lld", &n );

    printf("%lld", f(n) );

    return 0;
}