再起 - なんだかいろいろウィキ

＊＊数列の和

#include<stdio.h>
#include <stdlib.h>
int saiki(int );
int main(){
FILE *fp;
fp=fopen("../aaa.txt","r");
int a;
fscanf(fp,"%d",&a);
fclose(fp);
printf("%d\n",saiki(a));
return 0;
}
int saiki(int a){
if(a==1) return 1;
else return (saiki(a-1)+a);
}

階乗

#include<stdio.h>
#include <stdlib.h>
int saiki(int );
int main(){
FILE *fp;
fp=fopen("../aaa.txt","r");
int a;
fscanf(fp,"%d",&a);
fclose(fp);
printf("%d\n",saiki(a));
return 0;
}
int saiki(int a){
if(a==1) return 1;
else return (saiki(a-1)*a);
}

＊＊Ｐのn乗

#include<stdio.h>
#include <stdlib.h>
int saiki(int ,int );
int main(){
FILE *fp;
fp=fopen("../aaa.txt","r");
int p;
int n=5;
fscanf(fp,"%d",&p);
fclose(fp);
printf("%d\n",saiki(p,n));
return 0;
}
int saiki(int a,int n){
if(n>0) return (saiki(a,n-1)*a);
else return 1;
}

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