Pat a problem-1110. Complete binary tree (25)-(judging whether it is a full binary)

Test instructions: Determines whether a two-ary tree with a node n is a complete binary tree. Yes outputs the last node of the full binary tree, no output root node.

Achievements, and then respectively, the tree and the node tree is n two-tree comparison, statistics corresponding to the number of nodes, if n, is a complete binary tree, otherwise it is not.

#include <iostream>#include<cstdio>#include<algorithm>#include<string.h>using namespacestd;Const intmaxn= A;inttwo[6];intLastnode;structnode{intLeft,right; intID;} TREE[MAXN],CBT[MAXN];/*The input given by the two-fork tree and the node is a full binary tree of n is compared, calculate the corresponding number of nodes if the number of nodes is N, then the two-tree is a complete binary tree. I is the current node number of the complete binary tree. Root is the corresponding node of the input binary tree. */intCompareintRootintIintN) {    intres1=-1, res2=-1; if(root==-1){        return 0; }    if(i==N) lastnode=root;//record the ID of the last node of the full binary tree    intsum=0; if(2*i<=N) {Sum+=compare (tree[root].left,i*2, N); }    if(2*i+1<=N) {Sum+=compare (tree[root].right,i*2+1, N); }    BOOLflag1=false, flag2=false; if((2*i<=n&&tree[root].left!=-1)|| (2*i>n&&tree[root].left==-1)) Flag1=true; if((2*i+1<=n&&tree[root].right!=-1)|| (2*i+1>n&&tree[root].right==-1)) Flag2=true; if(Flag1 &&flag2) Sum++; returnsum;}intMain () {intN; scanf ("%d",&N); Charstr1[Ten],str2[Ten]; intA; intVIS[MAXN]; memset (Vis,-1,sizeof(VIS));  for(intI=0; i<n;i++) {scanf ("%s%s", STR1,STR2); Tree[i].id=i; if(str1[0]=='-') Tree[i].left=-1; Else{a=atoi (STR1); Tree[i].left=A; Vis[a]=1; }        if(str2[0]=='-') Tree[i].right=-1; Else{a=atoi (STR2); Tree[i].right=A; Vis[a]=1; }    }    intRoot;  for(intI=0; i<n;i++){        if(vis[i]==-1) Root=i; }    if(Compare (Root,1, n) = =N) {printf ("YES%d", Lastnode); }    Else{printf ("NO%d", Root); }    return 0;}

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The method of solving the problem in this blog is better than mine, that is, traversing the two-fork tree by the level, each traversing a node cnt++, until 1. At this time cnt=n, yes, otherwise no.

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Pat a problem-1110. Complete binary tree (25)-(judging whether it is a full binary)