The cows play the child's game of hopscotch in a non-traditional way. Instead of a linear set of numbered boxes into which to hop, the cows create a 5x5 rectilinear grid of digits parallel to the x and y axes.
They then adroitly hop onto any digit in the grid and hop forward, backward, right, or left (never diagonally) to another digit in the grid. They hop again (same rules) to a digit (potentially a digit already visited).
With a total of five intra-grid hops, their hops create a six-digit integer (which might have leading zeroes like 000201).
Determine the count of the number of distinct integers that can be created in this manner.
Input
* Lines 1..5: The grid, five integers per line
Output
* Line 1: The number of distinct integers that can be constructed
Sample Input
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1
Sample Output
15
Hint
OUTPUT DETAILS:
111111, 111112, 111121, 111211, 111212, 112111, 112121, 121111, 121112, 121211, 121212, 211111, 211121, 212111, and 212121 can be constructed. No other values are possible.
思路:最直接对每一个位置进行DFS,但是需要注意的是可以重复走,所以每次遍历时都是四个方向,只要不越界就可以;用set不重复的特性来记录总的步数
#include<iostream>
#include<cstdio>
#include<fstream>
#include<queue>
#include<vector>
#include<algorithm>
#include<cmath>
#include<set>
#include<cstring>
#define MAX 110000
#define INF 10000000
using namespace std;
int a[5][5];
int dix[4] = {1,-1,0,0};
int diy[4] = {0,0,-1,1};
set <int> hop;
int ans = 0;
//DFS
void Dfs(int x, int y, int pos, int num){
//返回的唯一条件是走了五步,返回时判断路径是否首次经过
if(pos == 5){
hop.insert(num);
return ;
}
//遍历
for(int i=0; i<4; i++){
int nx = x + dix[i];
int ny = y + diy[i];
if(nx>=0 && ny>=0 && nx<5 && ny <5){
Dfs(nx, ny, pos+1, num*10+a[nx][ny]);
}
}
}
//处理
void Solve(){
for(int i=0; i<5; i++)
for(int j=0; j<5; j++)
Dfs(i,j,0,a[i][j]);
cout << hop.size() << endl;
}
//测试函数
int main(){
ifstream in ("D:\\钢铁程序员\\程序数据\\034HopscotchPOJ3050.txt");//从文件读取数据流,省去手动输入的麻烦
if(!in){//读取如果失败
cout << "ERROR" << endl;
}
for(int i=0; i<5; i++)
for(int j=0; j<5; j++)
in >> a[i][j];
Solve();
in.close();//打开文件以后要关闭
return 0;
}