16進数のままで加減乗除

質問

２つの値を10進数でユーザーが入力して、それを16進数に変換し、16進数のままで加減乗除をするプログラムを考えています。ただ答えるだけではなく、筆算形式で答えを出さなければならないので、なかなかできません。教えてください。

回答No.3

jacta

こんな感じでしょうか？

#include <stdio.h>
#include <limits.h>

int table[][SCHAR_MAX+1] =
{
　['0'] =
　{
　　['0'] = 0,
　　['1'] = 1,
　　['2'] = 2,
　　['3'] = 3,
　　['4'] = 4,
　　['5'] = 5,
　　['6'] = 6,
　　['7'] = 7,
　　['8'] = 8,
　　['9'] = 9,
　　['a'] = 10,
　　['b'] = 11,
　　['c'] = 12,
　　['d'] = 13,
　　['e'] = 14,
　　['f'] = 15,
　},
　['1'] =
　{
　　['0'] = 1,
　　['1'] = 2,
　　['2'] = 3,
　　['3'] = 4,
　　['4'] = 5,
　　['5'] = 6,
　　['6'] = 7,
　　['7'] = 8,
　　['8'] = 9,
　　['9'] = 10,
　　['a'] = 11,
　　['b'] = 12,
　　['c'] = 13,
　　['d'] = 14,
　　['e'] = 15,
　　['f'] = 16,
　},
　['2'] =
　{
　　['0'] = 2,
　　['1'] = 3,
　　['2'] = 4,
　　['3'] = 5,
　　['4'] = 6,
　　['5'] = 7,
　　['6'] = 8,
　　['7'] = 9,
　　['8'] = 10,
　　['9'] = 11,
　　['a'] = 12,
　　['b'] = 13,
　　['c'] = 14,
　　['d'] = 15,
　　['e'] = 16,
　　['f'] = 17,
　},
　['3'] =
　{
　　['0'] = 3,
　　['1'] = 4,
　　['2'] = 5,
　　['3'] = 6,
　　['4'] = 7,
　　['5'] = 8,
　　['6'] = 9,
　　['7'] = 10,
　　['8'] = 11,
　　['9'] = 12,
　　['a'] = 13,
　　['b'] = 14,
　　['c'] = 15,
　　['d'] = 16,
　　['e'] = 17,
　　['f'] = 18,
　},
　['4'] =
　{
　　['0'] = 4,
　　['1'] = 5,
　　['2'] = 6,
　　['3'] = 7,
　　['4'] = 8,
　　['5'] = 9,
　　['6'] = 10,
　　['7'] = 11,
　　['8'] = 12,
　　['9'] = 13,
　　['a'] = 14,
　　['b'] = 15,
　　['c'] = 16,
　　['d'] = 17,
　　['e'] = 18,
　　['f'] = 19,
　},
　['5'] =
　{
　　['0'] = 5,
　　['1'] = 6,
　　['2'] = 7,
　　['3'] = 8,
　　['4'] = 9,
　　['5'] = 10,
　　['6'] = 11,
　　['7'] = 12,
　　['8'] = 13,
　　['9'] = 14,
　　['a'] = 15,
　　['b'] = 16,
　　['c'] = 17,
　　['d'] = 18,
　　['e'] = 19,
　　['f'] = 20,
　},
　['6'] =
　{
　　['0'] = 6,
　　['1'] = 7,
　　['2'] = 8,
　　['3'] = 9,
　　['4'] = 10,
　　['5'] = 11,
　　['6'] = 12,
　　['7'] = 13,
　　['8'] = 14,
　　['9'] = 15,
　　['a'] = 16,
　　['b'] = 17,
　　['c'] = 18,
　　['d'] = 19,
　　['e'] = 20,
　　['f'] = 21,
　},
　['7'] =
　{
　　['0'] = 7,
　　['1'] = 8,
　　['2'] = 9,
　　['3'] = 10,
　　['4'] = 11,
　　['5'] = 12,
　　['6'] = 13,
　　['7'] = 14,
　　['8'] = 15,
　　['9'] = 16,
　　['a'] = 17,
　　['b'] = 18,
　　['c'] = 19,
　　['d'] = 20,
　　['e'] = 21,
　　['f'] = 22,
　},
　['8'] =
　{
　　['0'] = 8,
　　['1'] = 9,
　　['2'] = 10,
　　['3'] = 11,
　　['4'] = 12,
　　['5'] = 13,
　　['6'] = 14,
　　['7'] = 15,
　　['8'] = 16,
　　['9'] = 17,
　　['a'] = 18,
　　['b'] = 19,
　　['c'] = 20,
　　['d'] = 21,
　　['e'] = 22,
　　['f'] = 23,
　},
　['9'] =
　{
　　['0'] = 9,
　　['1'] = 10,
　　['2'] = 11,
　　['3'] = 12,
　　['4'] = 13,
　　['5'] = 14,
　　['6'] = 15,
　　['7'] = 16,
　　['8'] = 17,
　　['9'] = 18,
　　['a'] = 19,
　　['b'] = 20,
　　['c'] = 21,
　　['d'] = 22,
　　['e'] = 23,
　　['f'] = 24,
　},
　['a'] =
　{
　　['0'] = 10,
　　['1'] = 11,
　　['2'] = 12,
　　['3'] = 13,
　　['4'] = 14,
　　['5'] = 15,
　　['6'] = 16,
　　['7'] = 17,
　　['8'] = 18,
　　['9'] = 19,
　　['a'] = 20,
　　['b'] = 21,
　　['c'] = 22,
　　['d'] = 23,
　　['e'] = 24,
　　['f'] = 25,
　},
　['b'] =
　{
　　['0'] = 11,
　　['1'] = 12,
　　['2'] = 13,
　　['3'] = 14,
　　['4'] = 15,
　　['5'] = 16,
　　['6'] = 17,
　　['7'] = 18,
　　['8'] = 19,
　　['9'] = 20,
　　['a'] = 21,
　　['b'] = 22,
　　['c'] = 23,
　　['d'] = 24,
　　['e'] = 25,
　　['f'] = 26,
　},
　['c'] =
　{
　　['0'] = 12,
　　['1'] = 13,
　　['2'] = 14,
　　['3'] = 15,
　　['4'] = 16,
　　['5'] = 17,
　　['6'] = 18,
　　['7'] = 19,
　　['8'] = 20,
　　['9'] = 21,
　　['a'] = 22,
　　['b'] = 23,
　　['c'] = 24,
　　['d'] = 25,
　　['e'] = 26,
　　['f'] = 27,
　},
　['d'] =
　{
　　['0'] = 13,
　　['1'] = 14,
　　['2'] = 15,
　　['3'] = 16,
　　['4'] = 17,
　　['5'] = 18,
　　['6'] = 19,
　　['7'] = 20,
　　['8'] = 21,
　　['9'] = 22,
　　['a'] = 23,
　　['b'] = 24,
　　['c'] = 25,
　　['d'] = 26,
　　['e'] = 27,
　　['f'] = 28,
　},
　['e'] =
　{
　　['0'] = 14,
　　['1'] = 15,
　　['2'] = 16,
　　['3'] = 17,
　　['4'] = 18,
　　['5'] = 19,
　　['6'] = 20,
　　['7'] = 21,
　　['8'] = 22,
　　['9'] = 23,
　　['a'] = 24,
　　['b'] = 25,
　　['c'] = 26,
　　['d'] = 27,
　　['e'] = 28,
　　['f'] = 29,
　},
　['f'] =
　{
　　['0'] = 15,
　　['1'] = 16,
　　['2'] = 17,
　　['3'] = 18,
　　['4'] = 19,
　　['5'] = 20,
　　['6'] = 21,
　　['7'] = 22,
　　['8'] = 23,
　　['9'] = 24,
　　['a'] = 25,
　　['b'] = 26,
　　['c'] = 27,
　　['d'] = 28,
　　['e'] = 29,
　　['f'] = 30,
　},
};

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

　int n = sizeof(unsigned int)*2;
　char lhs[n+1], rhs[n+1];
　sprintf(lhs, "%.*x", n, a);
　sprintf(rhs, "%.*x", n, b);

　printf("　 %s\n"
　　　　 "+) %s\n"
　　　　 "-----------\n",
　　　　 lhs, rhs);

　char result[1+n+1];
　int carry = 0;
　for (int i = n-1; i >= 0; i--)
　{
　　int t = table[lhs[i]][rhs[i]] + carry;　// 16進数のまま計算
　　if (t < 16)
　　{
　　　carry = 0;
　　}
　　else
　　{
　　　t -= 16;
　　　carry = 1;
　　}
　　result[i] = "0123456789abcdef"[t];
　}
　result[1+n] = '\0';

　printf("　 %s\n", result);
}

エラーチェックは手抜きです。

補足

足し算の方法ですね、大変参考になりました。引き算、掛け算はこのプログラムを参考にして何とかなりそうです。しかし、割り算の方法がすっかりお手上げです。ご面倒ですが、割り算の方法をご教授いただけましたら幸いです。

回答No.2

Tacosan

どこがわからないのか, 書いてもらえませんか?
「筆算ができない」というときと, 「筆算はできるけど表示ができない」というときでは全くアドバイスが変わってきます.
前者であれば #1 と同じ, 後者なら「どこまでできているのかわからんのでプログラムを見せてくれ」ってことになります.

回答No.1

koko_u_u

>ただ答えるだけではなく、筆算形式で答えを出さなければならないので、なかなかできません。

16 進数の筆算ができない、という意味ですか？
10 進数と方法は同じですよ。

補足

出力結果を筆算形式で表したいのです。つまり人間が紙に書いて計算するプロセスまで表したいのです。