oj.uz

답안 #792664

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
792664 2023-07-25T07:57:32 Z 반딧불(#10051) Line Town (CCO23_day1problem3) C++17
0 / 25
 1 ms 468 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const ll INF = 1e18;

struct segTree{
    int tree[1<<20];

    void init(int i, int l, int r){
        tree[i] = 0;
        if(l==r) return;
        int m = (l+r)>>1;
        init(i*2, l, m);
        init(i*2+1, m+1, r);
    }

    void update(int i, int l, int r, int x, int v){
        if(l==r){
            tree[i] = v;
            return;
        }
        int m = (l+r)>>1;
        if(x<=m) update(i*2, l, m, x, v);
        else     update(i*2+1, m+1, r, x, v);
        tree[i] = tree[i*2] + tree[i*2+1];
    }

    int findRight(int i, int l, int r, int x){
        if(r<x || !tree[i]) return r+1;
        if(l==r) return l;
        int m = (l+r)>>1;
        int tmp = findRight(i*2, l, m, x);
        if(tmp == m+1) return findRight(i*2+1, m+1, r, x);
        else return tmp;
    }

    int findLeft(int i, int l, int r, int x){
        if(x<l || !tree[i]) return l-1;
        if(l==r) return l;
        int m = (l+r)>>1;
        int tmp = findLeft(i*2+1, m+1, r, x);
        if(tmp == m) return findLeft(i*2, l, m, x);
        else return tmp;
    }
} tree;

void imp(){
    puts("-1");
    exit(0);
}

int n;
int arr[500002];

void input();
void solve();

int main(){
    input();
    solve();
}

void input(){
    scanf("%d", &n);
    for(int i=1; i<=n; i++) scanf("%d", &arr[i]);

    vector<int> vec;
    for(int i=1; i<=n; i++) if(arr[i]) vec.push_back(abs(arr[i]));
    sort(vec.begin(), vec.end());
    vec.erase(unique(vec.begin(), vec.end()), vec.end());
    for(int i=1; i<=n; i++){
        if(!arr[i]) continue;
        arr[i] = (lower_bound(vec.begin(), vec.end(), abs(arr[i])) - vec.begin() + 1) * (arr[i]<0 ? -1 : 1);
    }

    int odd1 = 0, even1 = 0;
    for(int i=1; i<=n; i++) if(arr[i] == 1){
        if(i%2) odd1++;
        else even1++;
    }
//    if(abs(odd1 - even1) > 1) imp();
}

ll ans;
ll prf[500002], suf[500002];

int c[500002];

void flip(int x){
    c[x] = -c[x];
    if(1<x) tree.update(1, 1, n-1, x-1, c[x] == c[x-1]);
    if(x<n) tree.update(1, 1, n-1, x, c[x] == c[x+1]);
}

void solve(){
    for(int i=0; i<=n+1; i++) prf[i] = suf[i] = INF;
    prf[0] = 0;
    suf[n+1] = 0;
    ll cnt = 0;
    int MX = 0;

    /// prf�� ���Ѵ�
    tree.init(1, 1, n-1);
    for(int i=1; i<=n; i++) c[i] = arr[i];
    for(int i=1; i<n; i++) if(c[i] == c[i+1]) tree.update(1, 1, n-1, i, 1);

    cnt = 0, MX = 0;
    for(int i=1; i<=n; i++){
        if(c[i] == -1){
            if(i >= MX) prf[i] = cnt;
            continue;
        }
        int j = i+1;
        while(j<=n && c[j] != c[j-1]) j++;
//        int j = tree.findRight(1, 1, n-1, i) + 1;
        if(j>n) break;
        MX = max(MX, j);

        cnt += j-i;
        flip(j), flip(i);
        if(MX<=i+1) prf[++i] = cnt;
    }

    /// suf�� ���Ѵ�
    tree.init(1, 1, n-1);
    for(int i=1; i<=n; i++) c[i] = arr[i];
    for(int i=1; i<n; i++) if(c[i] == c[i+1]) tree.update(1, 1, n-1, i, 1);

    cnt = 0, MX = n+1;
    for(int i=n; i>=1; i--){
        if(c[i] == 1){
            if(i <= MX) suf[i] = cnt;
            continue;
        }
        int j = i-1;
        while(j>=1 && c[j] != c[j+1]) j--;
//        int j = tree.findLeft(1, 1, n-1, i-1);
        if(j<1) break;
        MX = min(MX, j);

        cnt += i-j;
        flip(j), flip(i);
        if(MX>=i-1) suf[--i] = cnt;
    }

    ans = INF;
    for(int i=0; i<=n; i++) ans = min(ans, prf[i] + suf[i+1]);

    printf("%lld", ans == INF ? -1 : ans);
}

Compilation message

Main.cpp: In function 'void input()':
Main.cpp:66:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
Main.cpp:67:34: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |     for(int i=1; i<=n; i++) scanf("%d", &arr[i]);
      |                             ~~~~~^~~~~~~~~~~~~~~

Subtask #1
0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Runtime error 1 ms 468 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #2
0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Runtime error 1 ms 468 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #3
0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Runtime error 1 ms 468 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #4
0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Runtime error 1 ms 468 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #5
0 / 4.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Incorrect 0 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #6
0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Incorrect 0 ms 340 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #7
0 / 2.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Runtime error 1 ms 468 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -

Subtask #8
0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Runtime error 1 ms 468 KB Execution killed with signal 11
4 Halted 0 ms 0 KB -