Submission #932980

#	Time	Username	Problem	Language	Result	Execution time	Memory
932980		idiotcomputer	Nafta (COI15_nafta)	C++11	34 / 100	125 ms	113344 KiB

nafta

#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define f first 
#define s second
#define pb push_back
 
const int mxN = 4*1e6;
const int mxS = 2000;
int R,S;
int sums[mxN];
pii bounds[mxN];
int grid[mxN];
int vis[mxN];

int cnt = 0;
void bfs(int node){
    queue<int> queue;
    queue.push(node);
    int curr,r,s;
    bounds[cnt].f = mxS+1;
    bounds[cnt].s = -1;
    while (queue.size() > 0){
        curr = queue.front();
        queue.pop();
        if (vis[curr] != -1 || grid[curr] == -1){
            continue;
        }
        vis[curr] = cnt;
        sums[cnt] += grid[curr];
        r = curr / S;
        s = curr % S;
        bounds[cnt].f = min(bounds[cnt].f, s);
        bounds[cnt].s = max(bounds[cnt].s, s);
        if (r > 0){
            queue.push(curr - S);  
        } 
        if (r < R-1){
            queue.push(curr+S);
        }
        if (s > 0){
            queue.push(curr-1);
        }
        if (s < S-1){
            queue.push(curr+1);
        }
    }
    cnt++;
}

int res[mxS+1];
int tres[mxS+1];
int addon[mxS+1];
vector<vector<int>> cont(mxS);

void dcdp(int l, int r, int sl, int sr){
    int m = (l+r)/2;
    for (int idx : cont[m]){
        addon[bounds[idx].f-1] += sums[idx];
    }
    tres[m] = 0;
    int cadd = 0;
    int bidx = -1;
    for (int i = m-1; i >= sl; i--){
        cadd += addon[i];
        if (res[i] + cadd > tres[m]){
            tres[m] = res[i] + cadd;
            bidx = i;
        }
    }
    for (int idx : cont[m]){
        addon[bounds[idx].f-1] -= sums[idx];
    }
    if (l != m){
        dcdp(l,m-1,sl,bidx);        
    } 
    if (r != m){
        dcdp(m+1,r,bidx,sr);
    }
} 
 
int main()
{
    memset(sums,0,sizeof(sums));
    
    for (int i =0; i < mxN; i++){
        vis[i] = -1;
    }
    
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    
    cin >> R >> S; 
    
    string row;
    for (int i =0; i < R; i++){
        cin >> row;
        for (int j =0; j < S; j++){
            if (row[j] == '.'){
                grid[i*S+j] = -1;
            } else {
                grid[i*S+j] = row[j]-'0';
            }
        }    
    }
    for (int i = 0; i < R*S; i++){
        if (vis[i] == -1 && grid[i] != -1){
            bfs(i);
        }
    }

    
    for (int i =0; i < cnt; i++){
        bounds[i].f += 1;
        bounds[i].s += 1;
        for (int j = bounds[i].f; j <= bounds[i].s; j++){
            cont[j].pb(i);
        }
    }
   
    memset(res,0,sizeof(res));
    memset(addon,0,sizeof(addon));
    int tot;
    for (int i = 0; i < S; i++){
        dcdp(0,S,0,S);
        tot = 0;
        for (int j = 0; j <= S; j++){
           /// cout << tres[j] << " ";
            tot = max(tot,tres[j]);
        }
    //    cout << '\n';
        cout << tot << '\n';
        swap(tres,res);
    }
    return 0;
}

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 0 / 66