Submission #168879

# Submission time Handle Problem Language Result Execution time Memory
168879 2019-12-16T20:25:59 Z thecodingwizard Nafta (COI15_nafta) C++11
100 / 100
606 ms 94532 KB
//#pragma GCC optimize ("O3")
//#pragma GCC target ("sse4")

#include <bits/stdc++.h>

using namespace std;

template<class T> using min_heap = priority_queue<T, vector<T>, greater<T>>;

#define FOR(i, a, b) for (int i=a; i<(b); i++)
#define F0R(i, a) for (int i=0; i<(a); i++)
#define F0R1(i, a) for (int i=1; i<=(a); i++)
#define FORd(i, a, b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i, a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)
#define MIN(a, b) a = min(a, b)
#define MAX(a, b) a = max(a, b)

#define INF 1000000010
#define LL_INF 4500000000000000000LL
#define LSOne(S) (S & (-S))
#define EPS 1e-9
#define pA first
#define pB second
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define eb emplace_back
#define PI acos(-1.0)
// #define MOD (int)(2e+9+11)
#define MOD (int)(1e+9+7)
#define SET(vec, val, size) for (int i = 0; i < size; i++) vec[i] = val;
#define SET2D(arr, val, dim1, dim2) F0R(i, dim1) F0R(j, dim2) arr[i][j] = val;
#define SET3D(arr, val, dim1, dim2, dim3) F0R(i, dim1) F0R(j, dim2) F0R(k, dim3) arr[i][j][k] = val;
#define SET4D(arr, val, dim1, dim2, dim3, dim4) F0R(i, dim1) F0R(j, dim2) F0R(k, dim3) F0R(l, dim4) arr[i][j][k][l] = val;

#define lb lower_bound
#define ub upper_bound
#define sz(x) (int)x.size()
#define beg(x) x.begin()
#define en(x) x.end()
#define all(x) beg(x), en(x)
#define resz resize
#define SORT(vec) sort(all(vec))
#define RSORT(vec) sort(vec.rbegin(),vec.rend())

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vl;

// @formatter:off
// Source: Benq (https://github.com/bqi343/USACO) [Modified]
namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);
    template<class T> void reA(T A[], int sz);

    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class Arg, class... Args> void re(Arg& first, Args&... rest) {
        re(first); re(rest...);
    }

    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.pA,p.pB); }
    template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
    template<class T> void reA(T A[], int sz) { F0R(i, sz) re(A[i]); }

    void setupIO(const string &PROB = "") {
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
        if (PROB.length() != 0) {
            ifstream infile(PROB + ".in");
            if (infile.good()) {
                freopen((PROB + ".in").c_str(), "r", stdin);
                freopen((PROB + ".out").c_str(), "w", stdout);
            }
        }
    }
}
using namespace input;

namespace output {
    template<class T1, class T2> void prD(const pair<T1,T2>& x);
    template<class T, size_t SZ> void prD(const array<T,SZ>& x);
    template<class T> void prD(const vector<T>& x);
    template<class T> void prD(const set<T>& x);
    template<class T1, class T2> void prD(const map<T1,T2>& x);

    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T, size_t SZ> void pr(const array<T,SZ>& x);
    template<class T> void pr(const vector<T>& x);
    template<class T> void pr(const set<T>& x);
    template<class T1, class T2> void pr(const map<T1,T2>& x);

    template<class T> void prD(const T& x) { cout << x; cout.flush(); }
    template<class Arg, class... Args> void prD(const Arg& first, const Args&... rest) {
        prD(first); prD(rest...);
    }

    template<class T1, class T2> void prD(const pair<T1,T2>& x) {
        prD("{",x.pA,", ",x.pB,"}");
    }
    template<class T> void prDContain(const T& x) {
        prD("{");
        bool fst = 1; for (const auto& a: x) prD(!fst?", ":"",a), fst = 0; // const needed for vector<bool>
        prD("}");
    }
    template<class T, size_t SZ> void prD(const array<T,SZ>& x) { prDContain(x); }
    template<class T> void prD(const vector<T>& x) { prDContain(x); }
    template<class T> void prD(const set<T>& x) { prDContain(x); }
    template<class T1, class T2> void prD(const map<T1,T2>& x) { prDContain(x); }

    void psD() { prD("\n"); }
    template<class Arg> void psD(const Arg& first) {
        prD(first); psD(); // no space at end of line
    }
    template<class Arg, class... Args> void psD(const Arg& first, const Args&... rest) {
        prD(first," "); psD(rest...); // print w/ spaces
    }


    template<class T> void pr(const T& x) { cout << x; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
        pr(first); pr(rest...);
    }

    template<class T1, class T2> void pr(const pair<T1,T2>& x) {
        pr(x.pA, " ", x.pB);
    }
    template<class T> void prContain(const T& x) {
        bool fst = 1; for (const auto& a: x) pr(!fst?" ":"",a), fst = 0; // const needed for vector<bool>
    }
    template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
    template<class T> void pr(const vector<T>& x) { prContain(x); }
    template<class T> void pr(const set<T>& x) { prContain(x); }
    template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }

    void ps() { pr("\n"); }
    template<class Arg> void ps(const Arg& first) {
        pr(first); ps(); // no space at end of line
    }
    template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
        pr(first," "); ps(rest...); // print w/ spaces
    }
}
using namespace output;
// @formatter:on

/* ============================ */

#define MAXN 2100

struct FenwickTree {
public:
    vi ft;
    FenwickTree(int n) {
        ft.assign(n+1, 0);
    }
    void upd(int k, int v) {
        for (; k < sz(ft); k += LSOne(k)) ft[k] += v;
    }
    int qry(int k) {
        int sum = 0; for (; k; k -= LSOne(k)) sum += ft[k];
        return sum;
    }
};

int r, s;
char grid[2000][2000];

int leftmost, rightmost, ct;
int dx[4] = {-1,0,1,0};
int dy[4] = {0,1,0,-1};
void dfs(int i, int j) {
    MIN(leftmost, j);
    MAX(rightmost, j);
    ct += grid[i][j] - '0';
    grid[i][j] = '.';
    F0R(x, 4) {
        int a = i + dx[x], b = j + dy[x];
        if (a >= 0 && a < r && b >= 0 && b < s && grid[a][b] != '.') dfs(a, b);
    }
}

int gain[MAXN][MAXN];
int dp[MAXN][MAXN];
int dpTransition[MAXN][MAXN];

// works with condition that dpTransition[i][j] <= dpTransition[i+1][j]
void solveDP(int lo, int hi, int transitionLo, int transitionHi, int j) {
    if (lo > hi) return;
    int mid = (lo + hi)/2;
    // solve for dp[mid], dpTransition[mid]
    dp[mid][j] = -INF;
    FOR(k, max(transitionLo, mid), transitionHi+1) {
        int opt = (k==s?0:dp[k+1][j-1]) + gain[k][mid];
        if (dp[mid][j] < opt) {
            dp[mid][j] = opt;
            dpTransition[mid][j] = k;
        }
    }
    solveDP(lo, mid - 1, transitionLo, dpTransition[mid][j], j);
    solveDP(mid + 1, hi, dpTransition[mid][j], transitionHi, j);
}

int main() {
    setupIO();

    re(r, s);
    F0R(i, r) reA(grid[i], s);
    vector<pair<ii, int>> pools;
    F0R(i, r) {
        F0R(j, s) {
            if (grid[i][j] != '.') {
                leftmost = INF, rightmost = -INF, ct = 0;
                dfs(i, j);
                pools.pb({{leftmost+1, rightmost+1}, ct});
            }
        }
    }
    sort(all(pools));

    int n = s;

    // Step 1: Calculate gain
    FenwickTree FT(s+10);
    trav(pool, pools) {
        FT.upd(pool.pA.pA, pool.pB);
        FT.upd(pool.pA.pB+1, -pool.pB);
    }
    int poolIdx = 0;
    F0R(posCovered, s+1) {
        while (poolIdx < sz(pools) && pools[poolIdx].pA.pA-1 < posCovered) {
            // remove poolIdx
            auto pool = pools[poolIdx];
            FT.upd(pool.pA.pA, -pool.pB);
            FT.upd(pool.pA.pB+1, pool.pB);
            poolIdx++;
        }
        FOR(i, posCovered, s) {
            gain[i][posCovered] = FT.qry(i+1);
        }
    }

    F0R(j, s+1) {
        if (j == 0) {
            F0R(i, s+1) dp[i][j] = 0;
        } else {
            solveDP(0, s, 0, s, j);
        }
    }

    F0R1(i, s) {
        ps(dp[0][i]);
    }

    return 0;
}

Compilation message

nafta.cpp: In function 'int main()':
nafta.cpp:234:9: warning: unused variable 'n' [-Wunused-variable]
     int n = s;
         ^
nafta.cpp: In function 'void input::setupIO(const string&)':
nafta.cpp:85:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
                 freopen((PROB + ".in").c_str(), "r", stdin);
                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
nafta.cpp:86:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
                 freopen((PROB + ".out").c_str(), "w", stdout);
                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 2 ms 1144 KB Output is correct
2 Correct 3 ms 1144 KB Output is correct
3 Correct 2 ms 1144 KB Output is correct
4 Correct 3 ms 1016 KB Output is correct
5 Correct 2 ms 1016 KB Output is correct
6 Correct 2 ms 1016 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 1144 KB Output is correct
2 Correct 3 ms 1144 KB Output is correct
3 Correct 2 ms 1144 KB Output is correct
4 Correct 3 ms 1016 KB Output is correct
5 Correct 2 ms 1016 KB Output is correct
6 Correct 2 ms 1016 KB Output is correct
7 Correct 12 ms 5688 KB Output is correct
8 Correct 12 ms 5624 KB Output is correct
9 Correct 12 ms 6392 KB Output is correct
10 Correct 11 ms 5624 KB Output is correct
11 Correct 10 ms 5596 KB Output is correct
12 Correct 10 ms 5496 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 1144 KB Output is correct
2 Correct 3 ms 1144 KB Output is correct
3 Correct 2 ms 1144 KB Output is correct
4 Correct 3 ms 1016 KB Output is correct
5 Correct 2 ms 1016 KB Output is correct
6 Correct 2 ms 1016 KB Output is correct
7 Correct 12 ms 5688 KB Output is correct
8 Correct 12 ms 5624 KB Output is correct
9 Correct 12 ms 6392 KB Output is correct
10 Correct 11 ms 5624 KB Output is correct
11 Correct 10 ms 5596 KB Output is correct
12 Correct 10 ms 5496 KB Output is correct
13 Correct 606 ms 57592 KB Output is correct
14 Correct 600 ms 58456 KB Output is correct
15 Correct 604 ms 94532 KB Output is correct
16 Correct 559 ms 58464 KB Output is correct
17 Correct 471 ms 55636 KB Output is correct
18 Correct 469 ms 55760 KB Output is correct