刷LeetCode（13）——Roman to Integer

刷LeetCode（13）——Roman to Integer

Code it now ! https://leetcode.com/problems/roman-to-integer/description/

Given a roman numeral, convert it to an integer.

Input is guaranteed to be within the range from 1 to 3999.

这题跟前面的一题刚好相反，不做过多的讨论，直接进行解题，代码如下：

#include <iostream>
#include <vector>
#include <string.h>

using namespace std;

class Solution {
public:
int romanToInt(string s) {
size_t pos = 0 ;
int sum = 0,lastindex = 0;
char* c[4][10]={
{"","I","II","III","IV","V","VI","VII","VIII","IX"},
{"","X","XX","XXX","XL","L","LX","LXX","LXXX","XC"},
{"","C","CC","CCC","CD","D","DC","DCC","DCCC","CM"},
{"","M","MM","MMM"}
};

for( int i=3;i>=0;--i){
for( int j = 0; j<10 && c[i][j] ; ++j){
int len = strlen(c[i][j]);
if( !s.compare(pos,len,c[i][j]) ){
lastindex = j;
}
}

pos += strlen(c[i][lastindex]);

sum = 10*sum + lastindex;

}
return sum;
}
};

int main()
{
string str;
cin >> str;
cout << Solution().romanToInt(str) << endl;

return 0;
}