feat: added leetcode 983 solution (#111)

Author: Tahanima

Algorithms/Medium/983_MinimumCostForTickets/Solution.java

@@ -0,0 +1,31 @@
+class Solution {
+    int[] memo = new int[400];
+
+    public int solve(int i, int[] days, int[] costs) {
+        if (i >= days.length) {
+            return 0;
+        }
+
+        if (memo[i] > 0) {
+            return memo[i];
+        }
+
+        memo[i] = 1000000;
+        for (int j = 0; j < 3; j++) {
+            int next = days[i] + ((j == 0) ? 1 : ((j == 1) ? 7: 30));
+            int k = i;
+            
+            while (k < days.length && days[k] < next) {
+                k++;
+            }
+            
+            memo[i] = Math.min(memo[i], costs[j] + solve(k, days, costs));
+        }
+        
+        return memo[i];
+    }
+
+    public int mincostTickets(int[] days, int[] costs) {
+        return solve(0, days, costs);
+    }
+}