https://leetcode.com/problems/roman-to-integer/description/

s50600822 · Mar 17, 2024 · c9ebb64 · c9ebb64
1 parent b2061e9
commit c9ebb64
Showing 1 changed file with 36 additions and 0 deletions.
diff --git a/interview_prep/algorithm/java/ide_handicapped/roman_to_integer/Solution.java b/interview_prep/algorithm/java/ide_handicapped/roman_to_integer/Solution.java
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+class Solution {
+    public int romanToInt(String s) {
+        int num = 0;
+        int sum = 0;
+        for (int i = 0; i<s.length(); i++) {
+            switch(s.charAt(i)) {
+                case 'I': num = 1; break;
+                case 'V': num = 5; break;
+                case 'X': num = 10; break;
+                case 'L': num = 50; break;
+                case 'C': num = 100; break;
+                case 'D': num = 500; break;
+                case 'M': num = 1000; break;
+            }
+            sum += num;
+        }
+
+        for (int i = s.length()-1; i > 0; i--) {
+           if ( (s.charAt(i) == 'V') & (s.charAt(i-1) == 'I') ) sum = sum-2;
+           if ( (s.charAt(i) == 'X') & (s.charAt(i-1) == 'I') ) sum = sum-2;
+           if ( (s.charAt(i) == 'L' ) & (s.charAt(i-1) == 'X') ) sum = sum-20;
+           if ( (s.charAt(i) == 'C' ) & (s.charAt(i-1) == 'X') ) sum = sum-20;
+           if ( (s.charAt(i) == 'M' ) & (s.charAt(i-1) == 'C') ) sum = sum-200;
+           if ( (s.charAt(i) == 'D') & (s.charAt(i-1) == 'C') ) sum = sum-200;
+        }
+        return sum;
+    }
+
+    public static void main(String[] args) {
+        //https://leetcode.com/problems/roman-to-integer/
+        Solution sol = new Solution();
+        assert sol.romanToInt("III") == 3;
+        assert sol.romanToInt("LVIII") == 58;
+        assert sol.romanToInt("MCMXCIV") == 1994;
+    }
+}