1884. Pascal's Travels
Time Limit: 1.0 Seconds Memory Limit: 65536K
Total Runs: 339 Accepted Runs: 151
An n x n game board is populated with
integers, one nonnegative integer per square. The goal is to travel
along any legitimate path from the upper left corner to the lower right
corner of the board. The integer in any one square dictates how large a
step away from that location must be. If the step size would advance
travel off the game board, then a step in that particular direction is
forbidden. All steps must be either to the right or toward the bottom.
Note that a 0 is a dead end which prevents any further progress.
Consider the 4 x 4 board shown in Figure 1, where the solid circle
identifies the start position and the dashed circle identifies the
target. Figure 2 shows the three paths from the start to the target,
with the irrelevant numbers in each removed.
 |
 |
Figure 1
|
Figure 2
|
Input: The input contains data
for one to thirty boards, followed by a final line containing only the
integer -1. The data for a board starts with a line containing a single
positive integer n, 4 ≤ n ≤ 34, which is the number of rows
in this board. This is followed by n
rows of data. Each row contains n
single digits, 0-9, with no spaces between them.
Output: The output consists of one line for each board,
containing a single integer, which is the number of paths from the
upper
left corner to the lower right corner. There will be fewer than 263 paths for any board.
Warning:
Brute force methods examining every path will likely exceed the
allotted time limit. 64-bit integer values are available as long values in Java or long long values using the contest's
C/C++ compilers.
| Example input: |
Example output: |
4
2331
1213
1231
3110
4
3332
1213
1232
2120
5
11101
01111
11111
11101
11101
-1
|
3
0
7
|
Source: Mid-Central USA 2005; Pacific Northwest Regionals 2005
Submit List
Runs Forum Statistics
Tianjin University Online Judge v1.2.4
