/* This is a java program to perform arithmetic operations on numbers which are greater than size of the integers. */ import java.util.Scanner; public class BigNumber { static final int MAXDIGITS = 100; /* maximum length bignum */ static final int PLUS = 1; /* positive sign bit */ static final int MINUS = -1; /* negative sign bit */ char digits[]; /* represent the number */ int signbit; /* 1 if positive, -1 if negative */ int lastdigit; /* index of high-order digit */ BigNumber() { digits = new char[MAXDIGITS]; intToBigNumber(0); } void printBigNumber() { int i; if (signbit == MINUS) System.out.printf("- "); for (i = lastdigit; i >= 0; i--) System.out.printf("%c", '0' + digits[i]); System.out.printf("\n"); } void intToBigNumber(int s) { if (s >= 0) signbit = PLUS; else signbit = MINUS; for (int i = 0; i < MAXDIGITS; i++) digits[i] = (char) 0; lastdigit = -1; int t = Math.abs(s); while (t > 0) { lastdigit++; digits[lastdigit] = (char) (t % 10); t /= 10; } if (s == 0) lastdigit = 0; } BigNumber addBigNumber(BigNumber b) { int carry, i; BigNumber c = new BigNumber(); if (signbit == b.signbit) c.signbit = signbit; else { if (signbit == MINUS) { signbit = PLUS; c = b.subtractBigNumber(this); signbit = MINUS; } else { b.signbit = PLUS; c = this.subtractBigNumber(b); b.signbit = MINUS; } return c; } c.lastdigit = Math.max(lastdigit, b.lastdigit) + 1; carry = 0; for (i = 0; i <= c.lastdigit; i++) { c.digits[i] = (char) ((carry + digits[i] + b.digits[i]) % 10); carry = (carry + digits[i] + b.digits[i]) / 10; } c.zeroJustify(); return c; } BigNumber subtractBigNumber(BigNumber b) { int borrow, v, i; BigNumber c = new BigNumber(); if (signbit == MINUS || b.signbit == MINUS) { b.signbit = -b.signbit; c = addBigNumber(b); b.signbit = -b.signbit; return c; } if (compareBigNumber(b) == PLUS) { c = b.subtractBigNumber(this); c.signbit = MINUS; return c; } c.lastdigit = Math.max(lastdigit, b.lastdigit); borrow = 0; for (i = 0; i <= c.lastdigit; i++) { v = digits[i] - borrow - b.digits[i]; if (digits[i] > 0) borrow = 0; if (v < 0) { v = v + 10; borrow = 1; } c.digits[i] = (char) (v % 10); } c.zeroJustify(); return c; } int compareBigNumber(BigNumber b) { int i; if (signbit == MINUS && b.signbit == PLUS) return PLUS; if (signbit == PLUS && b.signbit == MINUS) return MINUS; if (b.lastdigit > lastdigit) return PLUS * signbit; if (lastdigit > b.lastdigit) return MINUS * signbit; for (i = lastdigit; i >= 0; i--) { if (digits[i] > b.digits[i]) return MINUS * signbit; if (b.digits[i] > digits[i]) return PLUS * signbit; } return 0; } void zeroJustify() { while (lastdigit > 0 && digits[lastdigit] == 0) lastdigit--; if (lastdigit == 0 && digits[0] == 0) signbit = PLUS; /* hack to avoid -0 */ } void digitShift(int d) { int i; if (lastdigit == 0 && digits[0] == 0) return; for (i = lastdigit; i >= 0; i--) digits[i + d] = digits[i]; for (i = 0; i < d; i++) digits[i] = 0; lastdigit += d; } BigNumber multiplyBigNumber(BigNumber b) { BigNumber row = new BigNumber(); BigNumber tmp = new BigNumber(); BigNumber c = new BigNumber(); int i, j; row.signbit = this.signbit; row.lastdigit = this.lastdigit; System.arraycopy(this.digits, 0, row.digits, 0, this.digits.length); for (i = 0; i <= b.lastdigit; i++) { for (j = 1; j <= b.digits[i]; j++) { tmp = c.addBigNumber(row); c = tmp; } row.digitShift(1); } c.signbit = signbit * b.signbit; c.zeroJustify(); return c; } BigNumber divideBigNumber(BigNumber b) { BigNumber row = new BigNumber(); BigNumber tmp = new BigNumber(); BigNumber c = new BigNumber(); int asign, bsign, i; c.signbit = signbit * b.signbit; asign = signbit; bsign = b.signbit; signbit = PLUS; b.signbit = PLUS; c.lastdigit = lastdigit; for (i = lastdigit; i >= 0; i--) { row.digitShift(1); row.digits[0] = digits[i]; c.digits[i] = 0; while (row.compareBigNumber(b) != PLUS) { c.digits[i]++; tmp = row.subtractBigNumber(b); row = tmp; } } c.zeroJustify(); signbit = asign; b.signbit = bsign; return c; } } public class ArithmeticOpsBigNumbers { public static void main(String[] args) { int a, b; BigNumber n1 = new BigNumber(); BigNumber n2 = new BigNumber(); BigNumber n3 = new BigNumber(); BigNumber zero = new BigNumber(); Scanner sc = new Scanner(System.in); while (sc.hasNextInt()) { a = sc.nextInt(); b = sc.nextInt(); System.out.printf("a = %d b = %d\n", a, b); n1.intToBigNumber(a); n2.intToBigNumber(b); n3 = n1.addBigNumber(n2); System.out.printf("Addition: "); n3.printBigNumber(); System.out.printf("Comparing Numbers a ? b: %d\n", n1.compareBigNumber(n2)); n3 = n1.subtractBigNumber(n2); System.out.printf("Subtraction: "); n3.printBigNumber(); n3 = n1.multiplyBigNumber(n2); System.out.printf("Multiplication: "); n3.printBigNumber(); zero.intToBigNumber(0); if (zero.compareBigNumber(n2) == 0) System.out.printf("Division: NaN \n"); else { n3 = n1.divideBigNumber(n2); System.out.printf("Division: "); n3.printBigNumber(); } } sc.close(); } } /* 12342424 12313423 a = 12342424 b = 12313423 Addition: 24655847 Comparing Numbers a ? b: -1 Subtraction: 29001 Multiplication: 151977487557352 Division: 1