2025-10-31 学习日记

#include <bits/stdc++.h>
using namespace std;
#define fo(i,l,r) for(int i=(l);i<=(r);++i)
#define ve vector
#define endl '\n'
using ll = long long;
using ull = unsigned long long;
using sr = string;
using db = double;
using dll = double long;
const int MOD=998244353;
const ll INF=1e18;
const int DIR[4][2] = {{1,0},{-1,0},{0,-1},{0,1}};
const int N = 105;
int r1,c1,r2,c2,n,m,T;
ve arr(N,ve<char>(N));
ve memet(N,ve(N,ve<int>(20,-1)));
int dfs(int r,int c,int t){
    int &res = memet[r][c][t];
    if(res!=-1) return res;
    if(abs(r2-r)+abs(c2-c)>T-t) return res = 0;
    if(t==T){
        if(r==r2&&c==c2) return res = 1;
        return res = 0;
    }
    int ans = 0;
    for(auto &d:DIR){
        int x = r + d[0],y = c + d[1];
        if(x>0&&x<=n&&y>0&&y<=m&&arr[x][y]!='*') ans += dfs(x,y,t+1);
    }
    return res = ans;
}
void solve(){
    cin>>n>>m>>T;
    fo(i,1,n){
        fo(j,1,m){
            cin>>arr[i][j];
        }
    }
    cin>>r1>>c1>>r2>>c2;
    cout<<dfs(r1,c1,0);
}
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
}