Fox Ciel wants to write a task for a programming contest. The task is: “You are given a simple undirected graph with n vertexes. Each its edge has unit length. You should calculate the number of shortest paths between vertex 1 and vertex 2.”
Same with some writers, she wants to make an example with some certain output: for example, her birthday or the number of her boyfriend. Can you help her to make a test case with answer equal exactly to k?
Input
The first line contains a single integer k (1 ≤ k ≤ 109).
Output
You should output a graph G with n vertexes (2 ≤ n ≤ 1000). There must be exactly k shortest paths between vertex 1 and vertex 2 of the graph.
The first line must contain an integer n. Then adjacency matrix G with n rows and n columns must follow. Each element of the matrix must be ‘N’ or ‘Y’. If G ij is ‘Y’, then graph G has a edge connecting vertex i and vertex j. Consider the graph vertexes are numbered from 1 to n.
The graph must be undirected and simple: G ii = ‘N’ and G ij = G ji must hold. And there must be at least one path between vertex 1 and vertex 2. It’s guaranteed that the answer exists. If there multiple correct answers, you can output any of them.
Examples
input
2
output
4
NNYY
NNYY
YYNN
YYNN
input
9
output
8
NNYYYNNN
NNNNNYYY
YNNNNYYY
YNNNNYYY
YNNNNYYY
NYYYYNNN
NYYYYNNN
NYYYYNNN
input
1
output
2
NY
YN
Note
In first example, there are 2 shortest paths: 1-3-2 and 1-4-2.
In second example, there are 9 shortest paths: 1-3-6-2, 1-3-7-2, 1-3-8-2, 1-4-6-2, 1-4-7-2, 1-4-8-2, 1-5-6-2, 1-5-7-2, 1-5-8-2.
Solution:
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <memory.h>
using namespace std;
char g[2010][2010];
int main() {
int k;
scanf("%d", &k);
if (k == 1) {
puts("2");
puts("NY");
puts("YN");
return 0;
}
int mx = 0;
for (int j = 0; j < 30; j++)
if (k & (1 << j)) {
mx = j;
}
memset(g, 'N', sizeof(g));
int n = 2;
int u = 1;
for (int j = 1; j <= mx; j++) {
n++;
g[u][n] = g[n][u] = 'Y';
int x = n;
n++;
g[u][n] = g[n][u] = 'Y';
int y = n;
int z;
if (j == mx) {
z = 2;
} else {
z = ++n;
}
g[x][z] = g[z][x] = 'Y';
g[y][z] = g[z][y] = 'Y';
u = z;
}
for (int j = mx - 1; j >= 0; j--) {
if (k & (1 << j)) {
int v = 3 * j + 2;
if (j == 0) v--;
int len = 2 * (mx - j);
for (int it = 0; it < len - 1; it++) {
n++;
g[v][n] = g[n][v] = 'Y';
v = n;
}
g[v][2] = g[2][v] = 'Y';
}
}
printf("%d\n", n);
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= n; j++) putchar(g[i][j]);
putchar('\n');
}
return 0;
}