solve 322.coin-change

Author: andavid

vscode/322.coin-change.java

@@ -0,0 +1,64 @@
+/*
+ * @lc app=leetcode id=322 lang=java
+ *
+ * [322] Coin Change
+ *
+ * https://leetcode.com/problems/coin-change/description/
+ *
+ * algorithms
+ * Medium (31.53%)
+ * Likes:    2135
+ * Dislikes: 85
+ * Total Accepted:    233.5K
+ * Total Submissions: 738.6K
+ * Testcase Example:  '[1,2,5]\n11'
+ *
+ * You are given coins of different denominations and a total amount of money
+ * amount. Write a function to compute the fewest number of coins that you need
+ * to make up that amount. If that amount of money cannot be made up by any
+ * combination of the coins, return -1.
+ *
+ * Example 1:
+ *
+ *
+ * Input: coins = [1, 2, 5], amount = 11
+ * Output: 3
+ * Explanation: 11 = 5 + 5 + 1
+ *
+ * Example 2:
+ *
+ *
+ * Input: coins = [2], amount = 3
+ * Output: -1
+ *
+ *
+ * Note:
+ * You may assume that you have an infinite number of each kind of coin.
+ *
+ */
+class Solution {
+  public int coinChange(int[] coins, int amount) {
+    if (amount < 1) {
+      return 0;
+    }
+
+    int[] dp = new int[amount + 1];
+    int sum = 0;
+
+    while (++sum <= amount) {
+      int min = -1;
+      for (int coin : coins) {
+        if (sum >= coin && dp[sum - coin] != -1) {
+          int temp = dp[sum - coin] + 1;
+          if (min < 0 || temp < min) {
+            min = temp;
+          }
+        }
+      }
+      dp[sum] = min;
+    }
+
+    return dp[amount];
+  }
+}
+