根据两种遍历序列建树

void (int &index, int inLeft, int inRight, int postLeft, int postRight) {    
    if (inLeft > inRight) return;    
    index = postRight;    
    int i = 0;    
    while (in[i] != post[postRight]) i++;    
    dfs(tree[index][0], inLeft, i - 1, postLeft, postLeft + (i - inLeft) - 1);    dfs(tree[index][1], i + 1, inRight, postLeft + (i - inLeft), postRight - 1); 
}