Submission #583060

#	Time	Username	Problem	Language	Result	Execution time	Memory
583060		MadokaMagicaFan	Paint By Numbers (IOI16_paint)	C++14	100 / 100	716 ms	164472 KiB

paint

#include <bits/stdc++.h>

using namespace std;

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;

#define all(v)          v.begin(),v.end()
#define sort(v)         sort(all(v))
#define endl            '\n'
#define forn(i,n)       for(int i = 0; i < n; ++i)
#define forbe(i,b,e)    for(int i = b; i < e; ++i)
#define forr(i,n)       for(int i = n-1; i >= 0; --i)
#define sz(v)           ((int)v.size())
#define pb              push_back
#define f               first
#define s               second

struct psum{
    vi f;
    vi _v;
    int n;

    psum(int _n) {
        n = _n;
        f.assign(n,0);
        _v.assign(n,0);
    }

    void add(int x, int v) { _v[x] += v; }

    void gen() {
        forn(i,n) {
            if (i) f[i] = f[i-1];
            f[i] += _v[i];
        }
    }

    int q(int x) {
        if (x < 0) return 0;
        return f[x];
    }

    int query(int l, int r) { return max(q(r) - q(l-1),0); }
};

string solve_puzzle(string s, vi c) {
    int n = sz(s);
    int k = sz(c);
    string ans = s;

    psum tr(n);
    psum trx(n);

    psum posseg(n+5);
    psum minseg(n+5);


    forn(i,n) if (s[i] == '_') tr.add(i,1);
    forn(i,n) if (s[i] == 'X') trx.add(i,1);

    tr.gen();
    trx.gen();

    vector<int> pdp[k];
    vector<int> sdp[k];

    forn(j,k) pdp[j].assign(n,-1);
    forn(j,k) sdp[j].assign(n,-1);

    int lst;
    forn(j,k) {
        lst = 1;
        forn(i,n - c[j]+1) {
            if (i+c[j]-1) pdp[j][i+c[j]-1] = pdp[j][i+c[j]-2];
            if (pdp[j][i+c[j]-1] != -1 && (!trx.query(i+c[j]-1,i+c[j]-1) && lst))
                continue;

            lst = 0;
            if (tr.query(i,i+c[j]-1) > 0) continue;
            if (j) {
                if (!i) continue;
                if (pdp[j-1][i-1] == i-1 || pdp[j-1][i-1] == -1) continue;
                if (trx.query(pdp[j-1][i-1]+1,i-1)) continue;
            } else {
                if (trx.query(0,i-1) > 0) continue;
            }
            lst = 1;

            pdp[j][i+c[j]-1] = i+c[j]-1;
        }
    }

    forr(j,k) {
        lst = 1;
        forr(i,n-c[j]+1) {
            if (i < n-1) sdp[j][i] = sdp[j][i+1];
            if (sdp[j][i] != -1 && (!trx.query(i,i) && lst))
                continue;

            lst = 0;
            if (tr.query(i,i+c[j]-1) > 0) continue;
            if (j == k-1) {
                if (trx.query(i+c[j],n-1) > 0) continue;
            } else {
                if (i+c[j] == n) continue;
                if (sdp[j+1][i+c[j]] == i+c[j] || sdp[j+1][i+c[j]] == -1) continue;
                if (trx.query(i+c[j],sdp[j+1][i+c[j]]-1)) continue;
            }
            lst = 1;
            sdp[j][i] = i;
        }
    }

    int il, ir;
    forn(j,k) {
        forn(i,n) {
            if (i + c[j] > n) break;
            if (j) {
                if (!i) continue;
                il = pdp[j-1][i-1];
                if (il == -1 || il == i-1) continue;
            } else {
                il = -1;
            }

            if (j == k-1) {
                ir = n;
            } else {
                if (i + c[j] == n) continue;
                ir = sdp[j+1][i+c[j]];
                if (ir == -1 || ir == i + c[j]) continue;
            }

            if (tr.query(i,i+c[j]-1) > 0) continue;
            if (trx.query(il+1, i-1)) continue;
            if (trx.query(i + c[j], ir-1)) continue;

            if (j) minseg.add(pdp[j-1][i-1]+1,1);
            else   minseg.add(0,1);
            minseg.add(i,-1);

            minseg.add(i+c[j],1);
            if (j!=k-1) minseg.add(sdp[j+1][i+c[j]],-1);

            posseg.add(i,1);
            posseg.add(i+c[j],-1);
        }
    }

    posseg.gen();
    minseg.gen();
    forn(i,n) {
        if (posseg.q(i) > 0) {
            if (minseg.q(i) > 0)
                ans[i] = '?';
            else
                ans[i] = 'X';
        }
        else
            ans[i] = '_';
    }
    return ans;
}

#ifdef ONPC
void solve() {
    int n, k;
    cin >> k;
    string s;
    cin >> s;
    vi c(k);
    forn(i,k)
        cin >> c[i];
    string ans = solve_puzzle(s,c);

    cout << ans << endl;
}

int main() {
    freopen("in", "r", stdin);
    solve();
}
#endif

• Subtask 1: 7 / 7
• Subtask 2: 3 / 3
• Subtask 3: 22 / 22
• Subtask 4: 27 / 27
• Subtask 5: 21 / 21
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10