// 絶対値が大きい方を取得
public static LongNumber getAbsoluteMax(LongNumber ln1, LongNumber ln2) {
int digit = Integer.max(ln1.getDigit(), ln2.getDigit());
LongNumber ln1tmp = getCloneOf(ln1, digit);
LongNumber ln2tmp = getCloneOf(ln2, digit);
for (int i = digit - 1; i >= 0; i--) {
if (ln1tmp.value[i] > ln2tmp.value[i]) return ln1;
if (ln1tmp.value[i] < ln2tmp.value[i]) return ln2;
}
return ln1;
}
public static LongNumber getCloneOf(LongNumber ln, int digit) {
if (digit < ln.getDigit()) {
System.err.println("invalid argument: 'ln.getDigit()' must be less than or equal to 'digit'");
System.exit(-1);
}
LongNumber ret = emptyLongNumber(digit);
ret.sign = ln.sign;
ret.value = ln.value;
return ret;
}
public LongNumber plus(LongNumber ln) {
if (this.sign * ln.sign < 0) {
// 異符号の場合
LongNumber lnNegative;
LongNumber lnPositive;
if (this.sign > 0) {
lnNegative = getCloneOf(ln);
lnPositive = getCloneOf(this);
} else {
lnNegative = getCloneOf(this);
lnPositive = getCloneOf(ln);
}
lnNegative.sign = 1;
return lnPositive.minus(lnNegative);
} else {
// 同符号の場合
// 和による繰り上がりは大きくて1桁
int newDigit = Integer.max(this.getDigit(), ln.getDigit()) + 1;
LongNumber ret = emptyLongNumber(newDigit);
ret.sign = this.sign;
for (int i = 0; i < this.getDigit(); i++) ret.value[i] += this.value[i];
for (int i = 0; i < ln.getDigit(); i++) ret.value[i] += ln.value[i];
for (int i = 0; i < newDigit - 1; i++) {
if (ret.value[i] >= MAX_OF_EACH_DIGIT) {
ret.value[i] -= MAX_OF_EACH_DIGIT;
ret.value[i + 1] += 1;
}
}
return ret.refresh();
}
}
public LongNumber multiple(LongNumber ln) {
int digit = this.getDigit() + ln.getDigit();
LongNumber ret = emptyLongNumber(digit);
ret.sign = this.sign * ln.sign;
for (int i = 0; i < this.getDigit(); i++) {
for (int j = 0; j < ln.getDigit(); j++) {
ret.value[i + j] += this.value[i] * ln.value[j];
}
}
int carry;
for (int i = 0; i < digit - 1; i++) {
carry = (int) ((double) ret.value[i] / MAX_OF_EACH_DIGIT);
ret.value[i] -= MAX_OF_EACH_DIGIT * carry;
ret.value[i + 1] += carry;
}
return ret.refresh();
}
// クローンを作成
public static LongNumber getCloneOf(LongNumber ln) {
return getCloneOf(ln, ln.getDigit());
/*
LongNumber ret = emptyLongNumber(ln.getDigit());
ret.sign = ln.sign;
ret.value = ln.value;
return ret;
*/
}
// 値を比較する.
// 上位にゼロがつまったケタがあっても良い.
public boolean equals(LongNumber ln) {
if (this.sign * ln.sign < 0) return false;
// ケタ数合わせ
int digit = Integer.max(this.getDigit(), ln.getDigit());
LongNumber ln1 = getCloneOf(this, digit);
LongNumber ln2 = getCloneOf(ln, digit);
for (int i = 0; i < digit; i++) {
if (ln1.value[i] != ln2.value[i]) return false;
}
return true;
}
// 上のケタがゼロだったら取り除く
public LongNumber refresh() {
int cnt = 0;
// ゼロである上位ケタ数を数える
// 一番下の位はゼロでいいので数えない
for (int i = this.getDigit() - 1; i > 0; i--) {
if (this.value[i] != 0) break;
cnt++;
}
int newDigit = this.getDigit() - cnt;
LongNumber ret = emptyLongNumber(newDigit);
if (newDigit == 1 && this.value[0] == 0) {
System.out.println(ret);
ret.sign = 1;
} else {
ret.sign = this.sign;
}
for (int i = 0; i < newDigit; i++) {
ret.value[i] = this.value[i];
}
return ret;
}
public LongNumber minus(LongNumber ln) {
if (this.sign * ln.sign < 0) {
// 異符号の場合
LongNumber lnTmp = getCloneOf(ln);
lnTmp.inverseSign();
return this.plus(lnTmp);
} else {
// 同符号の場合
// 同じ符号の引き算でケタは増えない
int newDigit = Integer.max(this.getDigit(), ln.getDigit());
LongNumber ret = getCloneOf(LongNumber.getAbsoluteMax(this, ln), newDigit);
LongNumber small = getCloneOf(LongNumber.getAbsoluteMin(this, ln), newDigit);
if (small.equals(ln)) {
ret.sign = 1;
} else {
ret.sign = -1;
}
for (int i = 0; i < newDigit; i++) {
if (ret.value[i] >= small.value[i]) {
ret.value[i] -= small.value[i];
} else {
ret.value[i + 1] -= 1;
ret.value[i] = ret.value[i] + MAX_OF_EACH_DIGIT - small.value[i];
}
}
return ret.refresh();
}
}
