>>647
#include <stdio.h>

main()
{
int S = 0, n;
for(n = 1; S + n < 100; n++){
S += n;
}
n--; // 足しすぎたので 1 引く
printf("n:%d S:%d\n", n, S);
S = 0;
n = 1;
while(S + n < 100){
S += n;
n++;
}
n--;
printf("n:%d S:%d\n", n, S);
}