```
int romanToInt(char* s) {
int a[32],k,i,j=0;
for(i=0;s[i]!='\0';i++)
{
if(s[i]=='I')
a[i]=1;
else if(s[i]=='V')
a[i]=5;
else if(s[i]=='X')
a[i]=10;
else if(s[i]=='L')
a[i]=50;
else if(s[i]=='C')
a[i]=100;
else if(s[i]=='D')
a[i]=500;
else
a[i]=1000;
j++;
}
k=a[j-1];
for(i=j-1;i>0;i--)
{
if(a[i]>a[i-1])
k=k-a[i-1];
else
k=k+a[i-1];
}
return k;
}
```