UVa 297 - Quadtrees

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传送门UVa 297 - Quadtrees

树的题目.

题意是给你两颗树, 然后让他们合并, 求黑色像素的值.

参考了别人的解题报告.

解题方法是先按题目给的值重建两棵树, 然后按要求合并成一棵树, 最后用BFS计算出总的像素.

通过这题也学到了很多.

详情见代码

#include <cstdio>#include <cstring>#include <cstdlib>using namespace std;struct node{    node *child[4];    char data;};node *Build(int &a, const char tree[]);node *Combine(node *root1, node *root2);void GetAnswer(node *root1, int n, int &ans);int main(){    //freopen("input.txt", "r", stdin);    int T;    scanf("%d", &T);    getchar();    while (T--)    {        node *root1, *root2;        char tree1[10000];        char tree2[10000];        scanf("%s", tree1);        getchar();        scanf("%s", tree2);        int a, b;        a = b = 0;        root1 = Build(a, tree1);        root2 = Build(b, tree2);        root1 = Combine(root1, root2);        int ans = 0;        GetAnswer(root1, 1, ans);        printf("There are %d black pixels.\n", ans);    }    return 0;}node *Build(int &a, const char tree[]){    node *root = (node *)malloc(sizeof(node));    root->data = tree[a];    for (int i = 0; i < 4; i++)        root->child[i] = 0;    if(tree[a] == 'p')        for (int i = 0; i < 4; i++)            root->child[i] = Build(++a, tree);    return root;}node *Combine(node *tree1, node *tree2){    if (tree1 == NULL)        return tree2;    else if (tree2 == NULL)        return tree1;    else if (tree1->data == 'f' || tree2->data == 'f')    {        node *tree1 = (node *)malloc(sizeof(node));        tree1->data = 'f';        for (int i = 0; i < 4; i++)            tree1->child[i] = 0;        return tree1;    }    if (tree2->data == 'p')        tree1->data = 'p';    for (int i = 0; i < 4; i++)        tree1->child[i] = Combine(tree1->child[i], tree2->child[i]);    return tree1;}void GetAnswer(node *root, int level, int &ans){    if (root)    {        //printf("%c", root->data);        if (root->data == 'f')        {            if (level == 1)                ans += 1024;            else if (level == 2)                ans += 256;            else if (level == 3)                ans += 64;            else if (level == 4)                ans += 16;            else if (level == 5)                ans += 4;            else if (level == 6)                ans += 1;        }        for (int i = 0; i < 4; i++)            GetAnswer(root->child[i], level + 1, ans);    }}

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