原题链接 Hopscotch Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 3968 Accepted: 2634 Description
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. Source
USACO 2005 November Bronze
#include <cstdio>#include <set>#include <iostream>using namespace std;int a[6][6];const int dx[4]={0,0,1,-1};const int dy[4]={1,-1,0,0};set<int> s;void dfs(int x,int y,int fsum,int deep){ if(deep==6){ s.insert(fsum * 10 + a[x][y]); return; } int nowsum=fsum * 10 + a[x][y]; for(int i=0;i<4;i++){ int nx=x+dx[i],ny=y+dy[i]; if(nx>=0 && nx < 5 && ny >= 0 && ny < 5){ dfs(nx,ny,nowsum,deep+1); } } return;}int main(){ for(int i=0;i<5;i++){ for(int j=0;j<5;j++){ scanf("%d",&a[i][j]); } } for(int i=0;i<5;i++){ for(int j=0;j<5;j++){ dfs(i,j,0,1); } } cout << s.size() << endl; return 0;}新闻热点
疑难解答
