UVA 297 - Quadtrees

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#define maxn 20000+10
using namespace std;
struct node
{
int data, flag;
node *ll, *l, *r, *rr;
};
int tmpi;
node* &build(int cur, char *s)
{
node *t;
t = (node*)malloc(sizeof(node));
t->data = 1024/(int)pow(4, cur);
if(s[tmpi] == 'p')
{
t->flag = 0;
++tmpi;
t->ll = build(cur+1, s);
++tmpi;
t->l = build(cur+1, s);
++tmpi;
t->r = build(cur+1, s);
++tmpi;
t->rr = build(cur+1, s);
}
else if(s[tmpi] == 'e')
{
t->flag = 1;
t->ll = NULL;
t->l = NULL;
t->r = NULL;
t->rr = NULL;
}
else
{
t->flag = 2;
t->ll = NULL;
t->l = NULL;
t->r = NULL;
t->rr = NULL;
}
return t;
}
void dfs(node *t, int &sum)
{
if(t == NULL) return;
if(t->flag == 2)
sum+=t->data;
dfs(t->ll, sum);
dfs(t->l, sum);
dfs(t->r, sum);
dfs(t->rr, sum);
return;
}
int main()
{
int t;
scanf("%d", &t);
while(t--)
{
char s1[2000], s2[2000];
scanf("%s%s", s1, s2);
int len1 = strlen(s1);
int len2 = strlen(s2);
int len = 0;
char s3[4000];
int st1 = 0, st2 = 0;
while(st2 < len1 && st2 < len2)
{
if(s1[st1] == s2[st2]) s3[len++] = s1[st1++], ++st2;
else
{
if(s1[st1] == 'f')
{
s3[len++] = s1[st1++];
if(s2[st2] == 'e')
++st2;
else{
++st2;
int tmp = 4;
for(int i = 0; i < tmp; ++i)
{
if(s2[st2] != 'p')
++st2;
else tmp+=4, ++st2;
}
}
}
else if(s2[st2] == 'f')
{
s3[len++] = s2[st2++];
if(s1[st1] == 'e')
++st1;
else{
++st1;
int tmp = 4;
for(int i = 0; i < tmp; ++i)
{
if(s1[st1] != 'p')
++st1;
else tmp+=4, ++st1;
}
}
}
else if(s1[st1] == 'p')
{
++st2;
s3[len++] = s1[st1++];
int tmp = 4;
for(int i = 0; i < tmp; ++i)
{
if(s1[st1] == 'p') tmp += 4;
s3[len++] = s1[st1++];
}
}
else if(s2[st2] == 'p')
{
s3[len++] = s2[st2++];
int tmp = 4;
for(int i = 0; i < tmp; ++i)
{
if(s2[st2] == 'p') tmp += 4;
s3[len++] = s2[st2++];
}
++st1;
}
}
}
while(st1 < len1) s3[len++] = s1[st1++];
while(st2 < len2) s3[len++] = s2[st2++];
s3[len] = '\0';
node *tree;
tmpi = 0;
tree = build(0, s3);
int ans = 0;
dfs(tree, ans);
printf("There are %d black pixels.\n", ans);
}
return 0;
}