oj.uz

Submission #580315

# Submission time Handle Problem Language Result Execution time Memory
580315 2022-06-21T05:12:27 Z 조영욱(#8357) Event Hopping (BOI22_events) C++17
0 / 100
 205 ms 12136 KB 
#include <bits/stdc++.h>
using namespace std;

int n,q;
typedef pair<int,int> P;
P arr[100000];
vector<int> pr;
const int sz=262144;
P seg[sz*2];
int table[100000][17];

P merge(P a,P b) {
    return a>b?a:b;
}

P sum(int l,int r,int node=1,int nodel=0,int noder=sz-1) {
    if (r<nodel||l>noder) {
        return P(-1,-1);
    }
    if (l<=nodel&&noder<=r) {
        return seg[node];
    }
    int mid=(nodel+noder)/2;
    return merge(sum(l,r,node*2,nodel,mid),sum(l,r,node*2+1,mid+1,noder));
}

void update(int i,P val) {
    i+=sz;
    seg[i]=val;
    while (i>1) {
        i/=2;
        seg[i]=merge(seg[i*2],seg[i*2+1]);
    }
}

int main(void) {
    scanf("%d %d",&n,&q);
    for(int i=0;i<n;i++) {
        scanf("%d %d",&arr[i].first,&arr[i].second);
        pr.push_back(arr[i].first);
        pr.push_back(arr[i].second);
    }
    sort(pr.begin(),pr.end());
    pr.erase(unique(pr.begin(),pr.end()),pr.end());
    for(int i=0;i<n;i++) {
        arr[i].first=lower_bound(pr.begin(),pr.end(),arr[i].first)-pr.begin();
        arr[i].second=lower_bound(pr.begin(),pr.end(),arr[i].second)-pr.begin();
        //printf("%d %d\n",arr[i].first,arr[i].second);
        update(arr[i].first,P(arr[i].second,i));
    }
    memset(table,-1,sizeof(table));
    for(int i=0;i<n;i++) {
        P val=sum(0,arr[i].second);
        //printf("%d %d\n",val.first,val.second);
        if (val.first>arr[i].second) {
            table[i][0]=val.second;
        }
        //printf("%d.\n",table[i][0]);
    }
    for(int j=1;j<17;j++) {
        for(int i=0;i<n;i++) {
            if (table[i][j-1]!=-1) {
                table[i][j]=table[table[i][j-1]][j-1];
            }
        }
    }
    for(int i=0;i<q;i++) {
        int s,e;
        scanf("%d %d",&s,&e);
        s--;
        e--;
        if (arr[e].second<arr[s].second) {
            printf("impossible\n");
            continue;
        }
        if (arr[e].first<=arr[s].second) {
            printf("1\n");
            continue;
        }
        int now=s;
        int ret=0;
        for(int j=16;j>=0;j--) {
            int nt=table[now][j];
            if (nt!=-1&&arr[nt].second<arr[e].first) {
                ret+=(1<<j);
                now=nt;
            }
        }
        printf("%d\n",ret+2);
    }
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:37:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     scanf("%d %d",&n,&q);
      |     ~~~~~^~~~~~~~~~~~~~~
events.cpp:39:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         scanf("%d %d",&arr[i].first,&arr[i].second);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:69:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |         scanf("%d %d",&s,&e);
      |         ~~~~~^~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 6996 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6996 KB Output is correct
2 Incorrect 3 ms 6996 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6996 KB Output is correct
2 Incorrect 3 ms 6996 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 6996 KB Output is correct
2 Incorrect 3 ms 6996 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 152 ms 10848 KB Output is correct
2 Correct 173 ms 10984 KB Output is correct
3 Correct 205 ms 11084 KB Output is correct
4 Incorrect 182 ms 12136 KB Output isn't correct
5 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 6996 KB Output isn't correct
2 Halted 0 ms 0 KB -