Submission #1034590

#	Time	Username	Problem	Language	Result	Execution time	Memory
1034590		mimi	Nafta (COI15_nafta)	C++17	100 / 100	391 ms	181476 KiB

nafta

#include <bits/stdc++.h>
#define ff first
#define ss second
#define pp push_back
#define all(x) (x).begin(),(x).end()
#define dbg(v)  cout << "Line(" << __LINE__ << ") -> " << #v << " = " << (v) << endl;
using namespace std;
using ll = long long;
using ld = long double;
using pii = pair <ll,ll>;
using pll = pair <ll,ll>;
using pld = pair <ld,ld>;
const char el ='\n';
const char sp = ' ';
const ll maxn = 3e3+5, mod = 1e9+7, maxN = 1e6;
const ll inf = 1e18L+3;
ll n,m,id[maxn][maxn],neg[maxn][maxn],sum[maxN],total[maxn],l_[maxN], dp[maxn][maxn], ti,movx[] = {0,0,1,-1}, movy[] = {1,-1,0,0};
char c[maxn][maxn];
map<ll,bool> mark;

void DFS(ll u, ll v)
{
    id[u][v] = ti;
    l_[ti] = min(l_[ti],v);
    sum[ti]+=c[u][v]-'0';
    for(ll i=0;i<4;++i)
    {
        ll x = u+movx[i], y = v+movy[i];
        if(x>0 && x<=n && y>0 && y<=m && c[x][y]!='.' && !id[x][y])  DFS(x,y);
    }
}

void input()
{
    fill(l_,l_+maxN,inf);
    cin>>n>>m;
    for(ll i=1;i<=m;++i)   dp[m][0] = -inf;
    for(ll i=1;i<=n;++i)
        for(ll j=1;j<=m;++j)   cin>>c[i][j];
    for(ll i=1;i<=n;++i){
        for(ll j=1;j<=m;++j){
            if(!id[i][j] && c[i][j]!='.'){
                ++ti;
                DFS(i,j);
            }
        }
    }
}

void prepare()
{
    for(ll j=1;j<=m;++j)
    {
        mark.clear();
        for(ll i=1;i<=n;++i)
        {
            if(c[i][j]=='.')    continue;
            if(mark[id[i][j]])  continue;
            mark[id[i][j]] = true;
            total[j]+=sum[id[i][j]];
            neg[l_[id[i][j]]][j]+=sum[id[i][j]];
        }
        for(ll i=1;i<=m;++i)   neg[i][j]+=neg[i-1][j];
    }
}

ll cost(ll l, ll r)
{
    return total[r]-neg[l][r];
}

void cal(ll l, ll r, ll optl, ll optr, ll j)
{
    if(l>r) return;
    ll mid = (l+r)/2,best = 0;
    for(ll i=optl; i<=min(mid,optr);++i)
    {
        ll money = dp[i-1][j-1] + cost(i-1,mid);
        if(money>dp[mid][j])
        {
            dp[mid][j] = money;
            best = i;
        }
    }
    cal(l,mid-1,optl,best,j);
    cal(mid+1,r,best,optr,j);
}

void solve()
{
    for(ll i=1;i<=m;++i)
    {
        cal(1,m,1,m,i);
        ll ans = 0;
        for(ll j=1;j<=m;++j)   ans = max(ans,dp[j][i]);
        cout<<ans<<el;
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ll test = 1;
    while(test-->0)
    {
        input();
        prepare();
        solve();
    }
    return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 66 / 66