# Java Solution for Reverse Integer

• Algorithm
1, My idea is to convert int value of the x to a string variable num which can be reversed each character every time.
2, I use an exception to check whether the generated number overflowed or not.

class Solution {
public int reverse(int x) {
String num = Integer.toString(x);
int length = num.length() - 1;
int result = 0;
StringBuffer sb = new StringBuffer();
if(x < 0) {
num = num.substring(1);
length--;
sb.append("-");
}
for (int i = length; i >= 0 ; i--) {
sb.append(num.charAt(i));
}
try {
result = Integer.valueOf(sb.toString());
} catch (java.lang.NumberFormatException e) {
result = 0;
}
return result;
}
}

Complexity Analysis

Time complexity: O(n).

• Algorithm
1, My idea is to convert int value of the x to a string variable num which can be reversed each character every time.
2, I use an exception to check whether the generated number overflowed or not.

``````public int reverse(int x) {
String num = Integer.toString(x);
int length = num.length() - 1;
int result = 0;
StringBuffer sb = new StringBuffer();
if (x < 0) {
num = num.substring(1);
length--;
sb.append("-");
}
for (int i = length; i >= 0; i--) {
sb.append(num.charAt(i));
}
try {
result = Integer.valueOf(sb.toString());
} catch (java.lang.NumberFormatException e) {
result = 0;
}
return result;
}
``````

Complexity Analysis

Time complexity: O(n).

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