1.問題描述
Given a roman numeral, convert it to an integer.
Input is guaranteed to be within the range from 1 to 3999.
2.分析
3.代碼
int map(const char ch)
{
switch (ch) {
case 'I': return 1;
case 'V': return 5;
case 'X': return 10;
case 'L': return 50;
case 'C': return 100;
case 'D': return 500;
case 'M': return 1000;
default: return 0;
}
}
int romanToInt(char* s) {
unsigned int length = strlen(s);
int sum = 0;
for (unsigned int i = 0; i < length; ++i) {
if (i == length-1) {
sum += map(s[i]);
break;
}
if (map(s[i]) >= map(s[i+1])) sum += map(s[i]);
if (map(s[i]) < map(s[i+1])) {
sum += -map(s[i]) +map(s[i+1]);
i++;
}
}
return sum;
}
