>>454
#include <stdio.h>

int main(){
int k,n,s;
printf("閾値(≧１０）を入力：");
scanf("%d",&k);
for(n=1,s=0;s<k;n++){s=s+n*n;};n--;
printf("n= %d, s(%d) = %d\n",n-1,n-1,s-(n*n));
printf("n= %d, s(%d) = %d\n",n,n,s);
return 0;
}