Create 3278.cpp

POJ/3278.cpp

@@ -0,0 +1,75 @@
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <stack>
+using namespace std;
+
+struct treenode
+{
+    int value;
+    treenode *plus,*reduce,*add;
+};
+
+typedef struct treenode tree;
+
+tree* root=NULL;
+
+stack<tree*> bus;
+stack<tree*> tmpbus;
+stack<tree*> answerbus;
+
+bool vis[100001];
+
+int main()
+{
+    int n,k;
+    scanf("%d %d",&n,&k);
+    root=new (nothrow) tree;
+    root->value=n;
+    bus.push(root);
+    int currentstep=-1;
+    while(answerbus.empty())
+    {
+        ++currentstep;
+        while(!bus.empty())
+        {
+            tree* father=bus.top();
+            vis[father->value]=true;
+            if(father->value==k)
+            {
+                answerbus.push(father);
+                break;
+            }
+            bus.pop();
+            int vplus=father->value*2,vreduce=father->value-1,vadd=father->value+1;
+            if(vplus<100001&&!vis[vplus])
+            {
+                tree* node=new (nothrow) tree;
+                node->value=vplus;
+                father->plus=node;
+                tmpbus.push(node);
+            }
+            if(vadd<100001&&!vis[vadd])
+            {
+                tree* node=new (nothrow) tree;
+                node->value=vadd;
+                father->add=node;
+                tmpbus.push(node);
+            }
+            if(vreduce>-1&&!vis[vreduce])
+            {
+                tree* node=new (nothrow) tree;
+                node->value=vreduce;
+                father->reduce=node;
+                tmpbus.push(node);
+            }
+        }
+        while(!tmpbus.empty())
+        {
+            bus.push(tmpbus.top());
+            tmpbus.pop();
+        }
+    }
+    printf("%d\n",currentstep);
+    return 0;
+}