Submission #638557

#	Time	Username	Problem	Language	Result	Execution time	Memory
638557		ShirleyM	T-Covering (eJOI19_covering)	C++14	15 / 100	1094 ms	724 KiB

covering

#include <bits/stdc++.h>
using namespace std;
#define int int64_t
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef vector<vii> vvii;
typedef vector<bool> vb;
typedef vector<vb> vvb;
#define x first
#define y second
#define pb push_back
#define loop(i,s,e) for(int i=s;i<e;i++)
#define loopr(i,s,e) for(int i=e-1;i>=s;i--)
#define chkmax(a,b) a=max(a,b)
#define chkmin(a,b) a=min(a,b)
#define all(a) a.begin(),a.end()
#define fast {ios_base::sync_with_stdio(false); cin.tie(0);}
const int inf = 1e11;
const int INF = 1e9;
const int mod = 1e9+7;

int n,m,k;
vvi g;
vii sp;
vvi st;
vvb s;
int ans=-1;

bool in_limits(int i, int j){
    return (i>=0 && i<n && j>=0 && j<m);
}

int best(int i, int j){
    int ans = g[i][j];
    vi a;
    vii d = {{-1,0}, {0,-1}, {0,1}, {1,0}};
    for(auto it : d){
        int di = it.x, dj = it.y;
        int ni = i+di, nj = j+dj;
        if(!in_limits(ni,nj)) continue;
        a.pb(g[ni][nj]);
    }
    if(a.size() <=2) return -1;
    sort(all(a), greater<int>());
    loop(ind,0,3) ans += a[ind];
    return ans;
}

int get_from_st(int i, int j, int st){
    if(st == -1) return best(i,j);
    int ans = g[i][j];
    int u = in_limits(i-1,j) ? g[i-1][j] : -inf;
    int d = in_limits(i+1,j) ? g[i+1][j] : -inf;
    int l = in_limits(i,j-1) ? g[i][j-1] : -inf;
    int ri = in_limits(i,j+1) ? g[i][j+1] : -inf;
    if(st==0) ans += u+d+l;
    if(st == 1) ans += u+d+ri;
    else if(st==2) ans += u+l+ri;
    else if(st==3) ans += d+l+ri;
    return ans;
}

void put(int i, int j, int state){
    if(st[i][j] != -1 && st[i][j] != state){
        cout << "No";
        exit(0);
    }
    st[i][j] = state;
}

bool ins(const ii& cur, set<ii>& taken){
    if(cur == ii{-1,-1}) return false;
    if(taken.find(cur) != taken.end()) return false;
    taken.insert(cur);
    return true;
}

bool legal(){
    set<ii> taken;
    loop(i,0,k){
        int r = sp[i].x, c = sp[i].y;
        ii u = in_limits(r-1,c) ? ii{r-1,c} : ii{-1,-1};
        ii d = in_limits(r+1,c) ? ii{r+1,c} : ii{-1,-1};
        ii l = in_limits(r,c-1) ? ii{r,c-1} : ii{-1,-1};
        ii ri = in_limits(r,c+1) ? ii{r,c+1} : ii{-1,-1};
        if(st[r][c] == 0){
            if(!ins(u,taken) || !ins(d, taken) || !ins(l, taken)) return false;
        }
        if(st[r][c] == 1){
            if(!ins(u,taken) || !ins(d, taken) || !ins(ri, taken)) return false;
        }
        if(st[r][c] == 2){
            if(!ins(u,taken) || !ins(l, taken) || !ins(ri, taken)) return false;
        }
        if(st[r][c] == 3){
            if(!ins(d,taken) || !ins(l, taken) || !ins(ri, taken)) return false;
        }
    }
    return true;
}

void calc(int ind, int tot){
    if(ind==k){
        if(!legal()) return;
        chkmax(ans, tot);
        return;
    }
    int r = sp[ind].x, c = sp[ind].y;
    loop(state,0,4){
        st[r][c] = state;
        int cur_add = get_from_st(r,c,state);
        if(cur_add < 0) continue;
        calc(ind+1, tot+cur_add);
        st[r][c] = -1;
    }
}

int32_t main() {
    fast;
    cin >> n >> m;
    g.resize(n, vi(m));
    st.resize(n, vi(m, -1));
    s.resize(n, vb(m, -1));
    loop(i,0,n) loop(j,0,m) cin >> g[i][j];
    cin >> k; sp.resize(k);
    loop(i,0,k){
        cin >> sp[i].x >> sp[i].y;
        s[sp[i].x][sp[i].y]=true;
    }
    calc(0,0);
    if(ans<0) cout << "No";
    else cout << ans;
    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 15 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 30