Create dp1.java

dp1.java

@@ -0,0 +1,38 @@
+//problem1
+class Solution {
+    public int coinChange(int[] coins, int amount) {
+        int n=coins.length;
+        int m=amount;
+        int[][] dp=new int[n+1][m+1];
+        for(int j=1;j<=m;j++){
+            dp[0][j]=amount+1;
+        }
+        for(int i=1;i<=n;i++){
+            for(int j=1;j<=m;j++){
+                if(coins[i-1]>j){
+                    dp[i][j]=dp[i-1][j];
+                }else{
+                    dp[i][j]=Math.min(dp[i-1][j],1+dp[i][j-coins[i-1]]);
+                }
+            }
+        }
+        int res=dp[n][m];
+        return res==amount+1?-1:res;
+    }
+}
+//problem2
+class Solution {
+    public int rob(int[] nums) {
+        if(nums.length==1) return nums[0];
+        int n=nums.length;
+        int temp;
+        int prev=nums[0];
+        int curr=Math.max(nums[0],nums[1]);
+        for(int i=2;i<n;i++){
+            temp=curr;
+            curr=Math.max(curr,nums[i]+prev);
+            prev=temp;
+        }
+        return curr;
+    }
+}