feat: coin change

Author: minji-go

coin-change/minji-go.java

@@ -0,0 +1,23 @@
+/*
+    Problem: https://leetcode.com/problems/coin-change/
+    Description: return the fewest number of coins that you need to make up that amount
+    Concept: Array, Dynamic Programming, Breadth-First Search
+    Time Complexity: O(N²), Runtime 15ms   - N is the amount
+    Space Complexity: O(N), Memory 44.28MB
+*/
+class Solution {
+    public int coinChange(int[] coins, int amount) {
+        int[] dp = new int[amount+1];
+        Arrays.fill(dp, amount+1);
+        dp[0]=0;
+
+        for(int i=1; i<=amount; i++){
+            for(int coin : coins){
+                if(i >= coin) {
+                    dp[i] = Math.min(dp[i], dp[i-coin] +1);
+                }
+            }
+        }
+        return dp[amount]>amount? -1: dp[amount];
+    }
+}