結果
問題 | No.1916 Making Palindrome on Gird |
ユーザー |
|
提出日時 | 2022-04-29 21:54:47 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 104 ms / 3,000 ms |
コード長 | 4,100 bytes |
コンパイル時間 | 2,173 ms |
コンパイル使用メモリ | 200,876 KB |
最終ジャッジ日時 | 2025-01-28 22:48:32 |
ジャッジサーバーID (参考情報) |
judge4 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 30 |
ソースコード
#include<bits/stdc++.h>using namespace std;#define rep(i,n) for(ll i=0;i<n;i++)#define repl(i,l,r) for(ll i=(l);i<(r);i++)#define per(i,n) for(ll i=(n)-1;i>=0;i--)#define perl(i,r,l) for(ll i=r-1;i>=l;i--)#define fi first#define se second#define pb push_back#define ins insert#define pqueue(x) priority_queue<x,vector<x>,greater<x>>#define all(x) (x).begin(),(x).end()#define CST(x) cout<<fixed<<setprecision(x)#define vtpl(x,y,z) vector<tuple<x,y,z>>#define rev(x) reverse(x);using ll=long long;using vl=vector<ll>;using vvl=vector<vector<ll>>;using pl=pair<ll,ll>;using vpl=vector<pl>;using vvpl=vector<vpl>;const ll MOD=1000000007;const ll MOD9=998244353;const int inf=1e9+10;const ll INF=4e18;const ll dy[9]={0,1,-1,0,1,1,-1,-1,0};const ll dx[9]={1,0,0,-1,1,-1,1,-1,0};template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b;return true;}return false;}template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b;return true;}return false;}const int mod = MOD;const int max_n = 200005;struct mint {ll x; // typedef long long ll;mint(ll x=0):x((x%mod+mod)%mod){}mint operator-() const { return mint(-x);}mint& operator+=(const mint a) {if ((x += a.x) >= mod) x -= mod;return *this;}mint& operator-=(const mint a) {if ((x += mod-a.x) >= mod) x -= mod;return *this;}mint& operator*=(const mint a) { (x *= a.x) %= mod; return *this;}mint operator+(const mint a) const { return mint(*this) += a;}mint operator-(const mint a) const { return mint(*this) -= a;}mint operator*(const mint a) const { return mint(*this) *= a;}mint pow(ll t) const {if (!t) return 1;mint a = pow(t>>1);a *= a;if (t&1) a *= *this;return a;}bool operator==(const mint &p) const { return x == p.x; }bool operator!=(const mint &p) const { return x != p.x; }// for prime modmint inv() const { return pow(mod-2);}mint& operator/=(const mint a) { return *this *= a.inv();}mint operator/(const mint a) const { return mint(*this) /= a;}};istream& operator>>(istream& is, mint& a) { return is >> a.x;}ostream& operator<<(ostream& os, const mint& a) { return os << a.x;}using vm=vector<mint>;using vvm=vector<vm>;struct combination {vector<mint> fact, ifact;combination(int n):fact(n+1),ifact(n+1) {assert(n < mod);fact[0] = 1;for (int i = 1; i <= n; ++i) fact[i] = fact[i-1]*i;ifact[n] = fact[n].inv();for (int i = n; i >= 1; --i) ifact[i-1] = ifact[i]*i;}mint operator()(int n, int k) {if (k < 0 || k > n) return 0;return fact[n]*ifact[k]*ifact[n-k];}}comb(max_n);mint dp[210][210][210];int main(){rep(i,210)rep(j,210)rep(k,210)dp[i][j][k]=0;ll h,w;cin >> h >> w;vector<string> g(h);rep(i,h)cin >> g[i];if(g[0][0]!=g[h-1][w-1]){cout << 0 << endl;return 0;}dp[0][0][h-1]=1;rep(i,(h+w-1)/2){rep(j,h){rep(k,h){if(dp[i][j][k]==0)continue;rep(s,2){ll ndx=j+dx[s],ndy=i-j+dy[s];if(ndx<0||ndy<0||ndx>=h||ndy>=w)continue;rep(d,2){ll nndx=k+dx[d+2],nndy=(h+w-2-i)-k+dy[d+2];if(nndx<0||nndy<0||nndx>=h||nndy>=w)continue;if(g[ndx][ndy]==g[nndx][nndy]){dp[i+1][ndx][nndx]+=dp[i][j][k];}}}}}}mint ans=0;if((h+w-1)&1){rep(i,210){ans+=dp[(h+w-1)/2][i][i];//if(dp[(h+w-1)/2][i][i]!=0)cout << i << " " << dp[(h+w-1)/2][i][i] << endl;}}else{rep(i,210)rep(j,210)rep(k,210){ll x=j,y=i-x;ll xx=k,yy=h+w-2-i-xx;if(x<0||y<0||x>=h||y>=w)continue;if(xx<0||yy<0||xx>=h||yy>=w)continue;if((x==xx&&y+1==yy)||(y==yy&&x+1==xx))ans+=dp[i][j][k];}}cout << ans << endl;}