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| #include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
#include <algorithm>
#include <limits.h>
using namespace std;
#define CLEAR_NEXTQ while (!nextQ.empty()) nextQ.pop();
#define MAX_SIZE 101
struct point
{
int x; int y;
point(){}
point(int X, int Y)
{
x = X; y = Y;
}
};
int n;
int steps;
int init[MAX_SIZE][MAX_SIZE];
int cur[MAX_SIZE][MAX_SIZE],prev[MAX_SIZE][MAX_SIZE];
queue<point> q,nextQ;
int moveX[4] = {0,1,0,-1};
int moveY[4] = {1,0,-1,0};
void input()
{
cin>>n>>steps;
for (int i=0;i<n;i++)
for (int j=0;j<n;j++)
scanf("%d",&init[i][j]);
}
bool correct(int x, int y)
{
if (x<0 || y<0)
return false;
if (x>=n || y>=n)
return false;
return true;
}
void solve()
{
q.push(point(0,0));
for (int i=1;i<steps;i++)
{
while (!q.empty())
{
point p = q.front();
q.pop();
for (int i=0;i<4;i++)
{
int x = p.x + moveX[i];
int y = p.y + moveY[i];
if (correct(x,y))
{
if (!cur[x][y])
nextQ.push(point(x,y));
cur[x][y] = max(cur[x][y],prev[p.x][p.y] + init[x][y]);
}
}
}
q = nextQ;
CLEAR_NEXTQ
for (int i=0;i<n;i++)
for (int j=0;j<n;j++)
{
prev[i][j] = cur[i][j];
cur[i][j] = 0;
}
}
int res = prev[0][0];
for (int i=0;i<n;i++)
for (int j=0;j<n;j++)
res = max(res,prev[i][j]);
cout<<res + init[0][0];
}
int main()
{
freopen("input.txt","r",stdin);
freopen("output.txt","w",stdout);
input();
solve();
return 0;
} |
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