Create 1900.cpp

QUSTOJ/1900.cpp

@@ -0,0 +1,91 @@
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+#include <algorithm>
+#include <queue>
+using namespace std;
+
+struct btree
+{
+    btree* l;
+    btree* r;
+    char v;
+};
+
+btree _node;
+btree* root=&_node;
+
+void deal(btree* n)
+{
+    scanf("%c",&n->v);
+    if(n->v=='#')
+    {
+        n->l=n->r=NULL;
+        return ;
+    }
+    else
+    {
+        n->l=new btree;
+        deal(n->l);
+        n->r=new btree;
+        deal(n->r);
+    }
+}
+void NLR(btree* n)
+{
+    if(n->v!='#')
+    {
+        printf("%c ",n->v);
+        if(n->l) NLR(n->l);
+        if(n->r) NLR(n->r);
+    }
+}
+void LNR(btree* n)
+{
+    if(n->v!='#')
+    {
+        if(n->l) LNR(n->l);
+        printf("%c ",n->v);
+        if(n->r) LNR(n->r);
+    }
+}
+
+void LRN(btree* n)
+{
+    if(n->v!='#')
+    {
+        if(n->l) LRN(n->l);
+        if(n->r) LRN(n->r);
+        printf("%c ",n->v);
+    }
+}
+
+void LEVEL(btree* n)
+{
+    queue<btree*> bus;
+    bus.push(n);
+
+    while(!bus.empty())
+    {
+        btree* p=bus.front();
+        bus.pop();
+        if(p->v!='#') printf("%c ",p->v);
+        if(p->l) bus.push(p->l);
+        if(p->r) bus.push(p->r);
+    }
+}
+
+int main()
+{
+    deal(root);
+    printf("Preorder:");
+    NLR(root);
+    printf("\nInorder:");
+    LNR(root);
+    printf("\nPostorder:");
+    LRN(root);
+    printf("\nLevelorder:");
+    LEVEL(root);
+    printf("\n");
+    return 0;
+}