标签：
题目描述：
Given two numbers represented as strings, return multiplication of the numbers as a string.
Note: The numbers can be arbitrarily large and are non-negative.
解题思路：
设置数组记录单个位置相乘的结果，最后负责相加进位。
代码如下：
public class Solution {
public String multiply(String num1, String num2) {
int num1Length = num1.length();
int num2Length = num2.length();
int d1, d2;
int carry = 0;
int temp;
int[] caculate = new int[num1Length + num2Length];
StringBuilder sb = new StringBuilder();
for (int i = num1.length() - 1; i >= 0; i--) {
d1 = num1.charAt(i) - ‘0‘;
for (int j = num2.length() - 1; j >= 0; j--) {
d2 = num2.charAt(j) - ‘0‘;
caculate[i + j + 1] += d1 * d2;
}
}
for (int i = caculate.length - 1; i >= 0; i--) {
temp = (caculate[i] + carry) % 10;
carry = (caculate[i] + carry) / 10;
caculate[i] = temp;
}
for (int num : caculate)
sb.append(num);
while (sb.length() > 1 && sb.charAt(0) == ‘0‘) {
sb.deleteCharAt(0);
}
return sb.toString();
}
}
Java [Leetcode 43]Multiply Strings
标签：
原文地址：http://www.cnblogs.com/zihaowang/p/5027514.html
