Submission #794286

#	Time	Username	Problem	Language	Result	Execution time	Memory
794286		puppy	Flip it and Stick it (CCO23_day2problem1)	C++17	25 / 25	6 ms	2216 KiB

Main

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <numeric>
#include <ctime>
#include <cstdlib>
using namespace std;
string s, t;
void flip(string &s)
{
    for (int i = 0; i < (int)s.size(); i++) {
        s[i] = s[i] == '0' ? '1' : '0';
    }
}
int minimum_cost(vector<int> v)
{
    int zr = accumulate(v.begin(), v.end(), 0), on = (int)v.size() - 1;
    if (zr > 2 * (on + 1)) return -1;
    int one = 0, zero = 0;
    vector<int> up;
    for (int i:v) {
        if (i == 1) one++;
        else if (i == 0) zero++;
        else if (i >= 3) up.push_back(i);
    }
    int req_one = 0;
    for (int &i:up) {
        if (i % 2 == 1) {
            req_one++; i--;
        }
    }
    int ans = 0;
    ans += req_one;
    if (one > req_one) {
        one -= req_one;
    }
    else {
        req_one -= one;
        one = 0;
        zero -= (req_one + 1) / 2;
    }
    int req_ev = 0;
    for (int i:up) req_ev += (i - 2) / 2;
    if (req_ev <= zero) {
        ans += req_ev;
    }
    else {
        ans += zero; req_ev -= zero;
        ans += req_ev * 2;
    }
    return ans;
}
int main()
{
    cin >> s >> t;
    int n = s.size();
    int k = t.size();
    if (k == 1) {
        bool ouc[2];
        for (int i = 0; i < n; i++) ouc[s[i]-'0'] = true;
        if (ouc[t[0]-'0']) cout << -1;
        else cout << 0;
    }
    else if (k == 2) {
        if (t[0] != t[1]) {
            if (t[0] == '1') flip(s);
            int ans = 0;
            for (int i = n - 1; i >= 0; i--) {
                if (s[i] == '1') continue;
                while (i > 0 && s[i-1] == '0') --i;
                ans++;
            }
            if (s[n-1] == '0') --ans;
            cout << ans;
        }
        else {
            if (t[0] == '1') flip(s);
            int ans = 0;
            int cnt = 0;
            for (int i = 0; i < n; i++) cnt += s[i] == '0';
            if (cnt > (n+1)/2) cout << -1;
            else {
                for (int i = 0; i < n; i++) {
                    if (s[i] == '1') continue;
                    int l = i;
                    while (i + 1 < n && s[i] == s[i+1]) i++;
                    int r = i;
                    ans += r - l;
                }
                cout << ans;
            }
        }
    }
    else {
        if (t[0] != t[2]) {
            if (t[0] == '1') {
                flip(s); flip(t);
            }
            if (t[1] == '1') {
                t[1] = '0';
                flip(s);
                reverse(s.begin(), s.end());
            }
            int cnt = 0;
            int st = n - 1;
            while (st >= 0 && s[st] == '0') st--;
            for (int i = st; i >= 0; i--) {
                if (s[i] == '1') continue;
                int l = i;
                while (i > 0 && s[i-1] == '0') i--;
                int r = i;
                cnt += l - r >= 1;
            }
            cout << cnt;
        }
        else if (t[0] != t[1]) {
            if (t[0] == '1') flip(s);
            int cnt = 0;
            for (int i = 1; i < n - 1; i++) {
                if (s[i-1] == '0' && s[i] == '1' && s[i+1] == '0') cnt++;
            }
            cout << (cnt + 1) / 2;
        }
        else {
            if (t[0] == '1') flip(s);
            vector<int> v;
            for (int i = 0; i < n; i++) {
                if (s[i] == '1') continue;
                int l = i;
                while (i < n - 1 && s[i+1] == '0') i++;
                int r = i;
                v.push_back(r - l + 1);
            }
            for (int i = 0; i < n - 1; i++) {
                if (s[i] == '1' && s[i+1] == '1') v.push_back(0);
            }
            if (s[0] == '1') v.push_back(0);
            if (s[n-1] == '1') v.push_back(0);
            cout << minimum_cost(v);
        }
    }
}

• Subtask 1: 1 / 1
• Subtask 2: 3 / 3
• Subtask 3: 4 / 4
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 7 / 7