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Submission #1077538

# Submission time Handle Problem Language Result Execution time Memory
1077538 2024-08-27T07:55:46 Z LIF Event Hopping (BOI22_events) C++14
100 / 100
 255 ms 20824 KB 
#include<bits/stdc++.h>
using namespace std;
int n,q,l[500005],r[500005],go[500005][30],pos[500005];
struct mn
{
    int val;
    int id;
}minn[800005];
struct nod
{
    int ll;
    int rr;
    int id;
}node[500005];
bool cmp(nod x,nod y)
{
   if(x.rr == y.rr)return x.ll < y.ll;
   else return x.rr < y.rr;
}
int read()
{
    int x=0,f=1;
    char ch = getchar();
    while(ch < '0' || ch > '9')
    {
        if(ch == '-')f = -1;
        ch = getchar();
    }
    while(ch >= '0' && ch <= '9')
    {
        x = (x<<3) + (x<<1) + (ch-'0');
        ch = getchar();
    }
    return x*f;
}
void pushup(int rt)
{
    if(minn[rt<<1].val < minn[rt<<1|1].val)
    {
        minn[rt].val = minn[rt<<1].val;
        minn[rt].id = minn[rt<<1].id;
    }
    else
    {
        minn[rt].val = minn[rt<<1|1].val;
        minn[rt].id = minn[rt<<1|1].id;
    }
    return;
}
pair<int,int> query(int l,int r,int queryl,int queryr,int rt)
{
    if(queryl <= l && r <= queryr)
    {
        return make_pair(minn[rt].val,minn[rt].id);
    }
    int mid = (l+r)>>1;
    pair<int,int> fir = make_pair(2e9,-1);
    if(mid >= queryl)
    {
        auto pp = query(l,mid,queryl,queryr,rt<<1);
        if(pp.first < fir.first)fir = pp;
    }
    if(mid + 1 <= queryr)
    {
        auto pp = query(mid+1,r,queryl,queryr,rt<<1|1);
        if(pp.first < fir.first)fir = pp;
    }
    return fir;
}
void build(int l,int r,int rt)
{
    if(l == r)
    {
        minn[rt].val = node[l].ll;
        minn[rt].id = l;
        return;
    }
    int mid = (l+r)>>1;
    build(l,mid,rt<<1);
    build(mid+1,r,rt<<1|1);
    pushup(rt);
    return;
}
int main()
{
    cin>>n>>q;
    for(int i=1;i<=n;i++)
    {
        l[i] = read();r[i] = read();
        nod temp = nod{l[i],r[i],i};
        node[i] = temp;
    }
    sort(node+1,node+n+1,cmp);
    build(1,n,1);
    for(int i=1;i<=n;i++)
    {
        go[i][0] = -1;
        int ll = 1,rr = i-1,last = -1;
        while (ll<=rr)
        {
            int mid = (ll+rr)>>1;
            if(node[mid].rr >= node[i].ll)
            {
                last = mid;
                rr = mid - 1;
            }
            else ll = mid + 1;
        }
        if(last <= 0)go[i][0] = -1;
        else
        {
            auto pp = query(1,n,last,i-1,1);
            go[i][0] = pp.second;
        }
    }
    for(int i=1;i<=n;i++)
    {
        pos[node[i].id] = i;
    }
    for(int i=1;i<=20;i++)
    {
        for(int j=1;j<=n;j++)
        {
            if(go[j][i-1] == -1)
            {
                go[j][i] = -1;
                continue;
            }
            go[j][i] = go[go[j][i-1]][i-1];
        }
    }
    // for(int i=1;i<=n;i++)
    // {
    //     cout<<node[i].ll<<" "<<node[i].rr<<endl;
    // }
    // for(int i=1;i<=n;i++)
    // {
    //     cout<<go[i][0]<<" ";
    // }
    // cout<<endl;
    // cout<<endl;
    while(q--)
    {
        int s,e;
        cin>>s>>e;
        if(e == s)
        {
            cout<<"0"<<endl;
            continue;
        }
        if(l[e] <= r[s] && r[s] <= r[e])
        {
            cout<<"1"<<endl;
            continue;
        }
        int now = pos[e];
        int ans = 0;
        bool can = true;
        for(int i=20;i>=0;i--)
        {
            int target = go[now][i];
            if(target == -1)continue;
            if(node[target].ll > r[s])
            {
                //cout<<"now: "<<now<<" target: "<<target<<endl;
                now = target;
                ans += pow(2,i);
            }
        }
        if(go[now][0] == -1)
        {
            can = false;
        }
        else
        {
            now = go[now][0];
            ans++;
        }
        //cout<<"last: "<<now<<endl;
        int ll = node[now].ll;
        int rr = node[now].rr;
        if(ll <= r[s] && r[s] <= rr)cout<<ans+1<<endl;
        else cout<<"impossible"<<endl;
    }
 
    return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:158:14: warning: variable 'can' set but not used [-Wunused-but-set-variable]
  158 |         bool can = true;
      |              ^~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 194 ms 19288 KB Output is correct
3 Correct 194 ms 20304 KB Output is correct
4 Correct 232 ms 20296 KB Output is correct
5 Correct 206 ms 20176 KB Output is correct
6 Correct 240 ms 20304 KB Output is correct
7 Correct 195 ms 20292 KB Output is correct
8 Correct 173 ms 20564 KB Output is correct
9 Correct 224 ms 20768 KB Output is correct
10 Correct 234 ms 20568 KB Output is correct
11 Correct 211 ms 20568 KB Output is correct
12 Correct 162 ms 20048 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 604 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 604 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 0 ms 348 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 604 KB Output is correct
14 Correct 1 ms 856 KB Output is correct
15 Correct 1 ms 600 KB Output is correct
16 Correct 1 ms 600 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Correct 1 ms 604 KB Output is correct
19 Correct 150 ms 2488 KB Output is correct
20 Correct 142 ms 2392 KB Output is correct
21 Correct 196 ms 2812 KB Output is correct
22 Correct 135 ms 2896 KB Output is correct
23 Correct 147 ms 2964 KB Output is correct
24 Correct 143 ms 2896 KB Output is correct
25 Correct 142 ms 2388 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 1 ms 604 KB Output is correct
4 Correct 1 ms 604 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 1 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 1 ms 604 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Correct 1 ms 604 KB Output is correct
13 Correct 1 ms 604 KB Output is correct
14 Correct 1 ms 604 KB Output is correct
15 Correct 1 ms 496 KB Output is correct
16 Correct 1 ms 604 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Correct 1 ms 604 KB Output is correct
19 Correct 39 ms 17748 KB Output is correct
20 Correct 36 ms 17236 KB Output is correct
21 Correct 45 ms 17668 KB Output is correct
22 Correct 42 ms 17864 KB Output is correct
23 Correct 50 ms 17748 KB Output is correct
24 Correct 44 ms 17812 KB Output is correct
25 Correct 31 ms 17144 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 216 ms 19284 KB Output is correct
2 Correct 190 ms 20304 KB Output is correct
3 Correct 195 ms 20112 KB Output is correct
4 Correct 175 ms 20824 KB Output is correct
5 Correct 224 ms 20560 KB Output is correct
6 Correct 212 ms 20276 KB Output is correct
7 Correct 235 ms 20244 KB Output is correct
8 Correct 218 ms 20560 KB Output is correct
9 Correct 40 ms 18516 KB Output is correct
10 Correct 193 ms 20052 KB Output is correct
11 Correct 189 ms 19672 KB Output is correct
12 Correct 206 ms 19892 KB Output is correct

Subtask #6
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 194 ms 19288 KB Output is correct
3 Correct 194 ms 20304 KB Output is correct
4 Correct 232 ms 20296 KB Output is correct
5 Correct 206 ms 20176 KB Output is correct
6 Correct 240 ms 20304 KB Output is correct
7 Correct 195 ms 20292 KB Output is correct
8 Correct 173 ms 20564 KB Output is correct
9 Correct 224 ms 20768 KB Output is correct
10 Correct 234 ms 20568 KB Output is correct
11 Correct 211 ms 20568 KB Output is correct
12 Correct 162 ms 20048 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 1 ms 604 KB Output is correct
16 Correct 1 ms 604 KB Output is correct
17 Correct 1 ms 604 KB Output is correct
18 Correct 1 ms 604 KB Output is correct
19 Correct 1 ms 604 KB Output is correct
20 Correct 1 ms 604 KB Output is correct
21 Correct 1 ms 604 KB Output is correct
22 Correct 0 ms 348 KB Output is correct
23 Correct 1 ms 348 KB Output is correct
24 Correct 1 ms 604 KB Output is correct
25 Correct 1 ms 604 KB Output is correct
26 Correct 1 ms 856 KB Output is correct
27 Correct 1 ms 600 KB Output is correct
28 Correct 1 ms 600 KB Output is correct
29 Correct 1 ms 604 KB Output is correct
30 Correct 1 ms 604 KB Output is correct
31 Correct 150 ms 2488 KB Output is correct
32 Correct 142 ms 2392 KB Output is correct
33 Correct 196 ms 2812 KB Output is correct
34 Correct 135 ms 2896 KB Output is correct
35 Correct 147 ms 2964 KB Output is correct
36 Correct 143 ms 2896 KB Output is correct
37 Correct 142 ms 2388 KB Output is correct
38 Correct 1 ms 348 KB Output is correct
39 Correct 0 ms 348 KB Output is correct
40 Correct 1 ms 604 KB Output is correct
41 Correct 1 ms 604 KB Output is correct
42 Correct 1 ms 604 KB Output is correct
43 Correct 1 ms 496 KB Output is correct
44 Correct 1 ms 604 KB Output is correct
45 Correct 1 ms 604 KB Output is correct
46 Correct 1 ms 604 KB Output is correct
47 Correct 39 ms 17748 KB Output is correct
48 Correct 36 ms 17236 KB Output is correct
49 Correct 45 ms 17668 KB Output is correct
50 Correct 42 ms 17864 KB Output is correct
51 Correct 50 ms 17748 KB Output is correct
52 Correct 44 ms 17812 KB Output is correct
53 Correct 31 ms 17144 KB Output is correct
54 Correct 216 ms 19284 KB Output is correct
55 Correct 190 ms 20304 KB Output is correct
56 Correct 195 ms 20112 KB Output is correct
57 Correct 175 ms 20824 KB Output is correct
58 Correct 224 ms 20560 KB Output is correct
59 Correct 212 ms 20276 KB Output is correct
60 Correct 235 ms 20244 KB Output is correct
61 Correct 218 ms 20560 KB Output is correct
62 Correct 40 ms 18516 KB Output is correct
63 Correct 193 ms 20052 KB Output is correct
64 Correct 189 ms 19672 KB Output is correct
65 Correct 206 ms 19892 KB Output is correct
66 Correct 0 ms 344 KB Output is correct
67 Correct 188 ms 20296 KB Output is correct
68 Correct 193 ms 20184 KB Output is correct
69 Correct 210 ms 20328 KB Output is correct
70 Correct 194 ms 20204 KB Output is correct
71 Correct 191 ms 20292 KB Output is correct
72 Correct 205 ms 20304 KB Output is correct
73 Correct 204 ms 20560 KB Output is correct
74 Correct 167 ms 20560 KB Output is correct
75 Correct 214 ms 20564 KB Output is correct
76 Correct 200 ms 20560 KB Output is correct
77 Correct 178 ms 20056 KB Output is correct
78 Correct 1 ms 344 KB Output is correct
79 Correct 1 ms 492 KB Output is correct
80 Correct 1 ms 600 KB Output is correct
81 Correct 1 ms 604 KB Output is correct
82 Correct 1 ms 604 KB Output is correct
83 Correct 1 ms 604 KB Output is correct
84 Correct 1 ms 600 KB Output is correct
85 Correct 1 ms 604 KB Output is correct
86 Correct 160 ms 2900 KB Output is correct
87 Correct 150 ms 2644 KB Output is correct
88 Correct 148 ms 2808 KB Output is correct
89 Correct 142 ms 2900 KB Output is correct
90 Correct 137 ms 2900 KB Output is correct
91 Correct 144 ms 2896 KB Output is correct
92 Correct 137 ms 2376 KB Output is correct
93 Correct 38 ms 18516 KB Output is correct
94 Correct 34 ms 17744 KB Output is correct
95 Correct 45 ms 18452 KB Output is correct
96 Correct 39 ms 18456 KB Output is correct
97 Correct 41 ms 18524 KB Output is correct
98 Correct 44 ms 18536 KB Output is correct
99 Correct 30 ms 17636 KB Output is correct
100 Correct 242 ms 20436 KB Output is correct
101 Correct 209 ms 20308 KB Output is correct
102 Correct 199 ms 20400 KB Output is correct
103 Correct 189 ms 20060 KB Output is correct
104 Correct 190 ms 19672 KB Output is correct
105 Correct 201 ms 20124 KB Output is correct
106 Correct 205 ms 19536 KB Output is correct
107 Correct 214 ms 19540 KB Output is correct
108 Correct 215 ms 20304 KB Output is correct
109 Correct 195 ms 20308 KB Output is correct
110 Correct 210 ms 20308 KB Output is correct
111 Correct 255 ms 20284 KB Output is correct