# 13. Roman to Integer

13. Roman to Integer

```class Solution {
public int romanToInt(String s) {
int out = 0;
for (int i = 0; i <s>= 0 &amp;&amp; s.charAt(i-1) == 'I'){
out -= 1;
out += 4;
}else out += 5;
}
//3
else if (s.charAt(i) == 'X'){
if ((i-1) &gt;= 0 &amp;&amp; s.charAt(i-1) == 'I'){
out -= 1;
out += 9;
}else out += 10;
}
//4
else if (s.charAt(i) == 'L'){
if ((i-1) &gt;= 0 &amp;&amp; s.charAt(i-1) == 'X'){
out -= 10;
out += 40;
}else out += 50;
}
//5
else if (s.charAt(i) == 'C'){
if ((i-1) &gt;= 0 &amp;&amp; s.charAt(i-1) == 'X'){
out -= 10;
out += 90;
}else out += 100;
}
//6
else if (s.charAt(i) == 'D'){
if ((i-1) &gt;= 0 &amp;&amp; s.charAt(i-1) == 'C'){
out -= 100;
out += 400;
}else out += 500;
}
//7
else if (s.charAt(i) == 'M'){
if ((i-1) &gt;= 0 &amp;&amp; s.charAt(i-1) == 'C'){
out -= 100;
out += 900;
}else out += 1000;
}
}
return out;
}
}
```

# 9. Palindrome Number

9. Palindrome Number

```class Solution {
public boolean isPalindrome(int x) {
if( x < 0 ) // negative
return false;
String nm = String.valueOf(x);
int start = 0;
int end = nm.length() -1;
while(start <= end){
if(nm.charAt(start) != nm.charAt(end)) return false;
start++;
end--;
}
return true;

}
}
```