UVa-1600 Patrol Robot

#include <bits/stdc++.h>

using namespace std;

struct Node
{
    int r,c,g;
    Node(int r,int c,int g): r(r),c(c),g(g) {}
    Node() {}
};

int m[22][22];

int rt,ct;
int k;
void read()
{
    memset(m,0,sizeof(m));
    cin >> rt >> ct >> k;
    for(int i = 0;i < rt;i ++)
        for(int j = 0; j < ct;j ++)
            cin >> m[i][j];
}

const int dr[] = {1,0,0,-1};
const int dc[] = {0,1,-1,0};

int d[22][22][22];
bool limit(Node v)
{
    return v.r>=0&&v.r<rt&&v.c>=0&&v.c<ct&&v.g<=k;
}
int solve()
{
    memset(d,-1,sizeof(d));
    queue<Node> q;
    q.push(Node(0,0,m[0][0]));
    d[0][0][m[0][0]] = 0;
    while(!q.empty())
    {
        Node u = q.front();q.pop();
        if(u.r==rt-1&&u.c==ct-1)    return d[u.r][u.c][u.g];
        for(int i = 0; i < 4;i ++)
        {
            Node v = u;v.r += dr[i];v.c += dc[i];
            if(limit(v)&&m[v.r][v.c]==0)    v.g = 0;
            if(limit(v)&&m[v.r][v.c]==1)    v.g ++;
            if(limit(v)&&d[v.r][v.c][v.g]<0)
            {
                d[v.r][v.c][v.g] = d[u.r][u.c][u.g] + 1;
                q.push(v);
            }
        }
    }
    return -1;
}

void print(int rnt)
{
    cout << rnt << endl;
}
int main()
{
    int T;
    cin >> T;
    while(T --)
    {
        read();
        int rnt = solve();
        print(rnt);
    }
    return 0;
}