Submission #292427

#	Time	Username	Problem	Language	Result	Execution time	Memory
292427		anonymous	Rope (JOI17_rope)	C++14	100 / 100	1830 ms	155136 KiB

rope

#include <iostream>
#include <vector>
#define MAXN 1000005
using namespace std;
int N, M, C[MAXN], Val[MAXN][2], Ans[MAXN];
vector <int> Pairs[MAXN][2];

class segtree {
    int ST[MAXN * 2];
public:
    void upd(int ind, int val) {
        for (ind += M, ST[ind] += val; ind > 1; ind >>= 1) {
            ST[ind >> 1] = max(ST[ind], ST[ind ^ 1]);
        }
    }
    int get() {return(ST[1]);}
} ST1, ST2;

int main() {
    //freopen("ropein.txt","r",stdin);
    scanf("%d %d",&N,&M);
    for (int i=1; i<=M; i++) {
        Ans[i] = N;
    }
    for (int i=1; i<=N; i++) {
        scanf("%d",&C[i]);
        Ans[C[i]] -= 1;
    }

    for (int i=1; i<N; i+=2) {
        Pairs[C[i]][0].push_back(C[i+1]);
        Pairs[C[i+1]][0].push_back(C[i]);
        Val[C[i]][0]++, Val[C[i+1]][0]++;
    }

    for (int i=2; i<N; i+=2) {
        Pairs[C[i]][1].push_back(C[i+1]);
        Pairs[C[i+1]][1].push_back(C[i]);
        Val[C[i]][1]++, Val[C[i+1]][1]++;
    }

    if (N%2) {
        Val[C[N]][0]++, Val[C[1]][1]++;
    } else {
        Val[C[1]][1]++, Val[C[N]][1]++;
    }

    for (int i=1; i<=M; i++) {
        ST1.upd(i, Val[i][0]);
        ST2.upd(i, Val[i][1]);
    }

    for (int i=1; i<=M; i++) {
        //solve case 1
        for (int v: Pairs[i][0]) {
            ST1.upd(v, -1);
        }
        ST1.upd(i, -1<<20);
        Ans[i] = min(Ans[i], N - ST1.get() - Val[i][0]);
        for (int v: Pairs[i][0]) {
            ST1.upd(v, 1);
        }
        ST1.upd(i, 1<<20);
        //solve case 2:
        for (int v: Pairs[i][1]) {
            ST2.upd(v, -1);
        }
        ST2.upd(i, -1<<20);
        Ans[i] = min(Ans[i], N - ST2.get() - Val[i][1]);
        for (int v: Pairs[i][1]) {
            ST2.upd(v, 1);
        }
        ST2.upd(i, 1<<20);
    }

    for (int i=1; i<=M; i++) {
        printf("%d\n",Ans[i]);
    }
}

Compilation message (stderr)

rope.cpp: In function 'int main()':
rope.cpp:21:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |     scanf("%d %d",&N,&M);
      |     ~~~~~^~~~~~~~~~~~~~~
rope.cpp:26:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   26 |         scanf("%d",&C[i]);
      |         ~~~~~^~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 30 / 30
• Subtask 3: 10 / 10
• Subtask 4: 25 / 25
• Subtask 5: 20 / 20