Zzuli_summerpractice (6) POJ 270...__ Summer Camp Training

G-pascal ' s travels p

Time Limit: 1000MS

Memory Limit: 65536K

64bit IO Format: %i64d &%i64u

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Description an n x N game board are 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. The integer in any one of the square dictates how large a is away from that location must. If the step size would advance travel off the game board, then a step in this particular direction is forbidden. All steps must is either to the right or toward the bottom. Note that the 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 the start identifies and the position IDE Ntifies the target. Figure 2 shows the three paths from the "start to" 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 <=, and 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 to each board, containing a single integer, which are the number of paths from the Upper left corner to the lower right corner. There is fewer than 2 paths for any board.

Sample Input

4

2331

1213

1231

3110

4

3332

1213

1232

2120

5

11101

01111

11111

11101

11101

-1

Sample Output

3

0

7

Hint Brute force methods examining every path would likely exceed the allotted time limit. 64-bit integer values are AVA Ilable as long values in Java or long long values using the contest ' s/C + + compilers.   is to give you a maze, and then each lattice has a number, to the value of the time you want to jump the corresponding steps, but can not jump out of the maze of the range, deep search is easy to time out, this introduction DP, direct seconds to kill, jump to the lattice, to jump to the grid corresponding value directly plus, the last one just Code: #include <stdio.h> #include <string.h> char map[55][55]; int n; __int64 NUM[50][50]; int main () {int i,j,k; while (scanf ("%d", &n), N!=-1) {for (i=0;i<n;i++) scanf ("%s", Map[i]); Memset (Num,0,sizeof ( num)); Num[0][0]=1; for (i=0;i<n;i++) for (j=0;j<n;j++) {k=map[i][j]-' 0 '; if (k==0) continue; if (j+k<n) num[i][j+k]+=num[i][j]; if ( i+k<n) Num[i+k][j]+=num[i][j]; printf ("%i64d\n", num[n-1][n-1]); return 0; }