Create CoinChange.java

Author: yuduozhou

CoinChange.java

@@ -0,0 +1,23 @@
+class Solution {
+    public int coinChange(int[] coins, int amount) {
+      if (amount == 0) return 0;
+      int[] change = new int[amount+1];
+      change[0] = 0;
+      for (int c : coins) {
+        if (c <= amount)
+          change[c] = 1;
+      }
+      for (int i = 1; i <= amount; i++) {
+        if (change[i] == 1) continue;
+        int min = -1;
+        for (int c:coins) {
+          if (i - c>0 && change[i-c] != -1) {
+            int withC = change[i-c] + 1;
+            min = min < 0 ? withC : Math.min(withC, min);
+          }
+        }
+        change[i] = min;
+      }
+      return change[amount];
+    }
+}