3_codeup_연습문제_재귀

1916.cpp

#include <stdio.h>

int fibo(int n, int a, int b){
    if (n==0) {
        return a;
    }
    fibo(n-1, b,(a+b)%10009);
}

int main(){
    int n;
    scanf("%d", &n);
    printf("%d", fibo(n, 0, 1));
    return 0;
}

1919.cpp

#include<stdio.h>
int sum;
int f(int n){
    if(n>0)    {
        sum = sum*10 + n%10;
        return f(n/10);
    }
    else
        return sum;
}
int main(){
    int a;
    scanf("%d",&a);
    printf("%d",f(a));
}

1920.cpp

#include <stdio.h>

void f(int k){
    if(k/2)
        f(k/2);
    printf("%d", k%2);
}

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

1929.cpp

#include <stdio.h>

void f(int k){
    if (k==1) ;
    else{
        if (k%2) f(3*k+1);
        else f(k/2);
    }
    printf("%d\n", k);
}

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

3420.cpp

#include <stdio.h>

void hanoi(int k, char from, char by, char to){
    if(!k) return;
    hanoi(k-1,from,to,by);
    printf("Disk %d : %c to %c\n", k, from, to);
    hanoi(k-1,by,from,to);
}

int main(){
    int n;
    scanf("%d", &n);
    hanoi(n,'A','B','C');
}

3421.cpp

#include <stdio.h>
int cnt=0;

void hanoi(int k, char from, char by, char to){
    if(!k) return;
    hanoi(k-1,from,to,by);
    cnt++;
    hanoi(k-1,by,from,to);
}

int main(){
    int n;
    scanf("%d", &n);
    hanoi(n,'A','B','C');
    printf("%d", cnt);
}
/*
#include <stdio.h>

int main(void)
{
    int n;
    scanf("%d",&n);
    printf("%d",(1<<n)-1);
}


#include <stdio.h>

int hanoi(int n){
    if(n==1) return 1;
    else return 2*hanoi(n-1)+1;
}

int main(){
    int n;
    scanf("%d", &n);
    printf("%d", hanoi(n));
    return 0;
}
*/

3704.cpp

#include<stdio.h>

int memo[100005] = {1, 1, 2};

int f(int k){
    if (memo[k]) return memo[k];
    else return memo[k] = (f(k-3) + f(k-2) + f(k-1)) % 1000;
}

int main(){
    int x;
    scanf("%d", &x);
    printf("%d", f(x));
}

/*
#include <stdio.h>
int main(){
    int n,i;
    int a[100005];
    scanf("%d",&n);
    a[0]=1;
    a[1]=1;
    a[2]=2;
    for(i=3;i<=n;i++)
        a[i]=(a[i-1]+a[i-2]+a[i-3])%1000;
    printf("%d",a[n]);
}
*/