剑指OFFER之二叉树中和为某一值的路径

第一行为2个整数n，k(1<=n<=10000)，n表示结点的个数，k表示要求的路径和，结点编号从1到n。

接下来有n行。这n行中每行为3个整数vi,leftnode,rightnode，vi表示第i个结点的值，leftnode表示第i个结点的左孩子结点编号，rightnode表示第i个结点的右孩子结点编号，若无结点值为-1。编号为1的结点为根结点。

5 22
10 2 3
5 4 5
12 -1 -1
4 -1 -1
7 -1 -1
1 5
1 -1 -1

result:
A path is found: 1 2 5
A path is found: 1 3
result:

注意：题目要求要按照字典序进行输出，做以下处理：选取值小的结点作为leftnode,值较大的结点作为rightnode.

Code:

#include <cstdio>
#include <vector>
#include <set>

using namespace std;

struct BinaryTreeNode{
    int data;
    int lchild;
    int rchild;
};void findPath(BinaryTreeNode Tree[],int root,int expectedSum,vector<int>& path,int currentSum){
    currentSum+=Tree[root].data;
    path.push_back(root);
    bool isLeaf=Tree[root].lchild==-1&&Tree[root].rchild==-1;
    if(currentSum==expectedSum&&isLeaf){
        printf("A path is found: ");
        vector<int>::iterator iter=path.begin();
        bool isFirst=true;
        for( ;iter!=path.end();++iter){
            if(isFirst){
                printf("%d",*iter);
                isFirst=false;
            }
            else
                printf(" %d",*iter);
        }
        printf("\n");
    }
    if(Tree[root].lchild!=-1){
        findPath(Tree,Tree[root].lchild,expectedSum,path,currentSum);
    }
    if(Tree[root].rchild!=-1){
        findPath(Tree,Tree[root].rchild,expectedSum,path,currentSum);
    }
    path.pop_back();
}

void startFind(BinaryTreeNode Tree[],int root,int expectedSum){
    if(root==-1)
        return;
    vector<int> path;
    int currentSum=0;
    findPath(Tree,root,expectedSum,path,currentSum);
}

int maxNum(int a,int b){
    return a>b?a:b;
}

int minNum(int a,int b){
    return a<b?a:b;
}

int main()
{
    int n,k;
    const int nodeNum=10010;
    BinaryTreeNode Tree[nodeNum];
    while(scanf("%d%d",&n,&k)!=EOF){
        int vi,leftNode,rightNode;
        for(int cnt=1;cnt<=n;++cnt){
            scanf("%d%d%d",&vi,&leftNode,&rightNode);
            Tree[cnt].data=vi;
            Tree[cnt].lchild=minNum(leftNode,rightNode);
            Tree[cnt].rchild=maxNum(leftNode,rightNode);
        }
        printf("result:\n");
        startFind(Tree,1,k);
    }
    return 0;
}

/**************************************************************
    Problem: 1368
    User: lcyvino
    Language: C++
    Result: Accepted
    Time:40 ms
    Memory:1568 kb
****************************************************************/