[pull] master from youngyangyang04:master

problems/0707.设计链表.md

@@ -380,10 +380,7 @@ class MyLinkedList {
             return;
         }
         size--;
-        if (index == 0) {
-            head = head.next;
-	    return;
-        }
+        //因为有虚拟头节点，所以不用对Index=0的情况进行特殊处理
         ListNode pred = head;
         for (int i = 0; i < index ; i++) {
             pred = pred.next;

problems/kamacoder/0053.寻宝-prim.md

@@ -521,6 +521,40 @@ int main() {
 ### Java 
 
 ### Python
+```python
+# 接收输入
+v, e = list(map(int, input().strip().split()))
+# 按照常规的邻接矩阵存储图信息，不可达的初始化为10001
+graph = [[10001] * (v+1) for _ in range(v+1)]
+for _ in range(e):
+    x, y, w = list(map(int, input().strip().split()))
+    graph[x][y] = w
+    graph[y][x] = w
+
+# 定义加入生成树的标记数组和未加入生成树的最近距离
+visited = [False] * (v + 1)
+minDist = [10001] * (v + 1)
+
+# 循环 n - 1 次，建立 n - 1 条边
+# 从节点视角来看：每次选中一个节点加入树，更新剩余的节点到树的最短距离，
+# 这一步其实蕴含了确定下一条选取的边，计入总路程 ans 的计算
+for _ in range(1, v + 1):
+    min_val = 10002
+    cur = -1
+    for j in range(1, v + 1):
+        if visited[j] == False and minDist[j] < min_val:
+            cur = j
+            min_val = minDist[j]
+    visited[cur] = True
+    for j in range(1, v + 1):
+        if visited[j] == False and minDist[j] > graph[cur][j]:
+            minDist[j] = graph[cur][j]
+
+ans = 0
+for i in range(2, v + 1):
+    ans += minDist[i]
+print(ans)
+```
 
 ### Go