提出 #4959797

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ソースコード 拡げる

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define REP(i,n) FOR(i,0,n)
#define FOR(i,a,b) for(int i=(a),i##Len_=(b);i<i##Len_;i++)
const char* LF = "\n";
namespace{struct _{_(){
    cin.tie(0);
    ios::sync_with_stdio(false);
}}a;}

signed main() {
    int N, K;
    cin >> N >> K;
    string S;
    cin >> S;

    vector<int> A;
    A.reserve(N);
    vector<int> A_;
    A_.reserve(N);
    vector<int> AS;
    AS.reserve(N);
    vector<int> B_;
    B_.reserve(N);
    vector<int> BS;
    BS.reserve(N);
    vector<int> E; //mode
    E.reserve(N);

    int cnt = 1;
    if (0 == N - 1) {
        A.push_back(cnt);
        E.push_back(S[0] == '0' ? 0 : 1);
    }

    FOR(i, 1, N) {
        if (S[i] != S[i-1]) {
            A.push_back(cnt);
            E.push_back(S[i-1] == '0' ? 0 : 1);
            cnt = 1;
        }
        else {
            cnt++;
        }
        if (i == N - 1) {
            A.push_back(cnt);
            E.push_back(S[i] == '0' ? 0 : 1);
        }
    }

    REP(i, A.size()) {
        if (E[i] == 0) {
            A_.push_back(A[i]);
        }
        else {
            B_.push_back(A[i]);
        }
    }

    int s_ = 0;
    AS.push_back(0);
    REP(i, A_.size()) {
        s_ += A_[i];
        AS.push_back(s_);
    }
    s_ = 0;
    BS.push_back(0);
    REP(i, B_.size()) {
        s_ += B_[i];
        BS.push_back(s_);
    }

    int ans = 0;
    const int NAS = AS.size();
    const int NBS = BS.size();
    
    REP(i, K) {
        AS.push_back(AS[NAS-1]);
        BS.push_back(BS[NBS-1]);
    }

    for (int i=0; i<NBS-(K); i++) {
        int a = BS[min(i+(K+1), NBS-1)] - BS[i];
        a += AS[min(i+K, NAS)] - AS[i];
        if (a > ans) ans = a;
    }

    cout << ans << LF;

    return 0;
}

提出情報

ジャッジ結果