Created
November 18, 2022 04:05
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| import 'dart:convert'; | |
| import 'dart:io'; | |
| void main() { | |
| String a = stdin.readLineSync(); | |
| String b = stdin.readLineSync(); | |
| print (multiplication(a.trim(), b.trim())); | |
| } | |
| String multiplication (String a, String b) { | |
| if (a.length == 0 || b.length == 0) { | |
| return '0'; | |
| } | |
| int sumLength = a.length + b.length; | |
| List<int> result = List.filled(a.length + b.length, 0); | |
| int index1 = 0; | |
| for(int i = (a.length - 1); i >= 0; i--) { | |
| int index2 = 0; | |
| int surplus = 0; | |
| for(int j = (b.length - 1); j >= 0; j--) { | |
| int sum = int.parse(a[i]) * int.parse(b[j]) + surplus + result[sumLength - (index1 + index2) - 1]; | |
| result[sumLength - (index1 + index2) - 1] = sum % 10; | |
| surplus = (sum / 10).toInt(); | |
| index2 ++; | |
| } | |
| if (surplus != 0) { | |
| result[sumLength - (index1 + index2) - 1] = surplus; | |
| } | |
| index1 ++; | |
| } | |
| if (result.every((e) => e == 0)) { | |
| return '0'; | |
| } | |
| String s = ''; | |
| for (var e in result) { | |
| if (!(result.indexOf(e) == 0 && e == 0)) | |
| s = s + e.toString(); | |
| } | |
| return s; | |
| } | |
| import "dart:io"; | |
| void main() { | |
| String num1 = stdin.readLineSync(); | |
| String tempNum1 = num1; | |
| String num2 = stdin.readLineSync(); | |
| String tempNum2 = num2; | |
| // Check negative | |
| if (num1[0] == "-" && num2[0] != "-") { | |
| num1 = num1.substring(1); | |
| } else if (num1[0] != "-" && num2[0] == "-") { | |
| num2 = num2.substring(1); | |
| } else if (num1[0] == "-" && num2[0] == "-") { | |
| num1 = num1.substring(1); | |
| num2 = num2.substring(1); | |
| } | |
| String s1 = num1; | |
| String s2 = num2; | |
| s1 = num1.split('').reversed.join(); | |
| s2 = num2.split('').reversed.join(); | |
| int lengthList = s1.length + s2.length; | |
| List<int> m = []; | |
| for (int i = 0; i < lengthList; i++) { | |
| m.addAll([0]); | |
| } | |
| for (int i = 0; i < s1.length; i++) { | |
| for (int j = 0; j < s2.length; j++) { | |
| m[i + j] = | |
| m[i + j] + (s1[i].codeUnitAt(0) - 48) * (s2[j].codeUnitAt(0) - 48); | |
| } | |
| } | |
| // print(m); | |
| String product = ""; | |
| for (int i = 0; i < m.length; i++) { | |
| int digit = m[i] % 10; | |
| int carry = m[i] ~/ 10; | |
| if (i + 1 < m.length) { | |
| m[i + 1] = m[i + 1] + carry; | |
| } | |
| product = digit.toString() + product; | |
| } | |
| while (product.length > 1 && product[0] == "0") { | |
| product = product.substring(1); | |
| } | |
| if (tempNum1[0] == '-' && tempNum2[0] != '-') { | |
| product = "-" + product; | |
| } else if (tempNum1[0] != '-' && tempNum2[0] == '-') { | |
| product = "-" + product; | |
| } | |
| print(product); | |
| } |
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