https://codeforces.com/contest/1182/problem/B

题解：暴力 

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
#define endl "\n"
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=1000+10;
const int M=100000+10;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,p,l,r,u,v;
int ans,cnt,flag,temp,sum;
int a[N][N];
char str[N][N];
struct node{};
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    //ios::sync_with_stdio(false);
    //cin.tie(0);
    //cout.tie(0);
    //scanf("%d",&t);
    //while(t--){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++)scanf("%s",str[i]+1);
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            if(str[i][j]=='*'&&str[i-1][j]=='*'&&str[i+1][j]=='*'&&str[i][j-1]=='*'&&str[i][j+1]=='*'){
                for(int k=j;k<=m;k++){
                    if(str[i][k]!='*')
                        break;
                    a[i][k]=1;
                }
                for(int k=j;k>=1;k--){
                    if(str[i][k]!='*')
                        break;
                    a[i][k]=1;
                }
                for(int k=i;k<=n;k++){
                    if(str[k][j]!='*')
                        break;
                    a[k][j]=1;
                }
                for(int k=i;k>=1;k--){
                    if(str[k][j]!='*')
                        break;
                    a[k][j]=1;
                }
                ans=1;
                break;
            }
        }
        if(ans)break;
    }
    for(int i=1;i<=n&&ans;i++){
        for(int j=1;j<=m&&ans;j++){
            if(str[i][j]=='*'&&!a[i][j]){
                ans=0;
            }
        }
    }
    cout<<(ans?"YES":"NO")<<endl;
    //}

#ifdef DEBUG
	printf("Time cost : %lf s\n",(double)clock()/CLOCKS_PER_SEC);
#endif
    //cout << "Hello world!" << endl;
    return 0;
}