Multiply Strings Total 溢出解法

Multiply Strings

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Question
 Solution 

public class Solution {
public String multiply(String num1, String num2) {
Solution solu = new Solution();
int n1 = solu.stringtonum(num1);
int n2 = solu.stringtonum(num2);
int sum1 = n1 * n2 ;
StringBuilder sb = new StringBuilder();
String y;

if (sum1 == 0) {
y = "0";
}
else
{
while (sum1 != 0) {
int k = sum1 % 10;
sb.append(k);
sum1 = sum1 / 10;
}
sb.reverse();
y = sb.toString();
}
return y;
}
public int stringtonum(String s)
{
int sum = 0 ;
for (int i = 0;i < s.length() ; i++ ) {
sum *= 10;
sum += (int)(s.charAt(i)) - (int)'0';
}
return sum;

}
}总结：

-2.6花了两个小时，从写出代码，到弄懂它是溢出解法。效率低，因为我对阅读理解他人的代码有抵触，因为阅读理解别人累。