/* =============================================== :::: DETAILS :::: Author : Harsh Mehta, Date : June 2024, Type : Easy Problem, No. 13 =============================================== :::: PROBLEM :::: * Given a roman numeral, convert it to an integer. * * Example 1: * Input: s = "III" * Output: 3 * Explanation: III = 3. * * Example 2: * Input: s = "LVIII" * Output: 58 * Explanation: L = 50, V= 5, III = 3. * * Example 3: * Input: s = "MCMXCIV" * Output: 1994 * Explanation: M = 1000, CM = 900, XC = 90 and IV = 4. =============================================== :::: STATS :::: TIME : 2ms , Beats 100.00% of users with Java MEMORY : 44.45mb Beats 73.53% of users with Java =============================================== :::: SOLUTION :::: * This code converts a Roman numeral string to an integer. * It first maps each Roman numeral to its corresponding integer value. * Then it sums these values while accounting for subtractive combinations (e.g., IV = 4) by checking if a numeral is less than the next one. =============================================== */ class Solution { public int romanToInt(String s) { int val = 0, p = 0; for (char ch: s.toCharArray()) { switch(ch) { case 'I': val+=1;p=1; break; case 'V': val+=(p==1)?3:5;p=5; break; case 'X': val+=(p==1)?8:10;p=10; break; case 'L': val+=(p==10)?30:50;p=50; break; case 'C': val+=(p==10)?80:100;p=100; break; case 'D': val+=(p==100)?300:500;p=500; break; case 'M': val+=(p==100)?800:1000;p=1000; break; } } return val; } }