背包理论基础01背包-1 js 版本修改

problems/背包理论基础01背包-1.md

@@ -380,44 +380,31 @@ func main() {
 ### javascript 
 
 ```js
-function testweightbagproblem (wight, value, size) {
-  const len = wight.length, 
-    dp = array.from({length: len + 1}).map(
-      () => array(size + 1).fill(0)
-    );
+function testWeightBagProblem (weight, value, size) {
+    // 定义 dp 数组
+    const len = weight.length,
+          dp = Array(len).fill().map(() => Array(size + 1).fill(0));
 
-  for(let i = 1; i <= len; i++) {
-    for(let j = 0; j <= size; j++) {
-      if(wight[i - 1] <= j) {
-        dp[i][j] = math.max(
-          dp[i - 1][j], 
-          value[i - 1] + dp[i - 1][j - wight[i - 1]]
-        )
-      } else {
-        dp[i][j] = dp[i - 1][j];
-      }
+    // 初始化
+    for(let j = weight[0]; j <= size; j++) {
+        dp[0][j] = value[0];
     }
-  }
 
-//   console.table(dp);
-
-  return dp[len][size];
-}
-
-function testWeightBagProblem2 (wight, value, size) {
-  const len = wight.length, 
-    dp = Array(size + 1).fill(0);
-  for(let i = 1; i <= len; i++) {
-    for(let j = size; j >= wight[i - 1]; j--) {
-      dp[j] = Math.max(dp[j], value[i - 1] + dp[j - wight[i - 1]]);
+    // weight 数组的长度len 就是物品个数
+    for(let i = 1; i < len; i++) { // 遍历物品
+        for(let j = 0; j <= size; j++) { // 遍历背包容量
+            if(j < weight[i]) dp[i][j] = dp[i - 1][j];
+            else dp[i][j] = Math.max(dp[i - 1][j], dp[i - 1][j - weight[i]] + value[i]);
+        }
     }
-  }
-  return dp[size];
-}
 
+    console.table(dp)
+
+    return dp[len - 1][size];
+}
 
 function test () {
-  console.log(testWeightBagProblem([1, 3, 4, 5], [15, 20, 30, 55], 6));
+    console.log(testWeightBagProblem([1, 3, 4, 5], [15, 20, 30, 55], 6));
 }
 
 test();