Submission #847183

#	Time	Username	Problem	Language	Result	Execution time	Memory
847183		vjudge1	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	262 ms	15156 KiB

skyscraper

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define task "test1"
#define minpos(x, y) (a[x] <= a[y] ? (x) : (y))
#define pll pair<ll, ll>
#define pii pair<int, int>

using namespace std;

int const nmax = 3e4+3;
int const mod = 1e9+7;
int const LG = 20;
int const bl=100;

void open_file()
{
    if(fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
}

void fast()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

struct ok{
    int dis,i,p;
};

bool operator > (ok a,ok b){
    return a.dis>b.dis;
}

int n,m;
int b[nmax],p[nmax];
int dp[nmax][bl+1];
vector<int> doge[nmax];

void input()
{
    cin >> n >> m;
    for(int i=0;i<m;i++){
        cin >> b[i] >> p[i];
        doge[b[i]].push_back(i);
    }
}

void NGU()
{
    int ans=1e9;
    priority_queue<ok,vector<ok>,greater<ok>> q;
    q.push({0,b[0],0});
    memset(dp,0x3f,sizeof(dp)); 
    dp[b[0]][0]=0;
    while(!q.empty()){
        ok top=q.top();
        q.pop();
        int dis=top.dis;
        int pk=top.p;
        int i=top.i;
        if(i==b[1]){
            ans=min(ans,dis);
            continue;
        }
        if(dis!=dp[i][pk]) continue;
        if(pk==0){
            for(auto x : doge[i]){
                if(p[x]<=bl){
                    if(dp[i][p[x]]>dis){
                        dp[i][p[x]]=dis;
                        q.push({dp[i][p[x]],i,p[x]});
                    }
                }
                else{
                    int bc=p[x];
                    int cnt=0;
                    for(int j=i;j<n;j+=bc){
                        if(dp[j][0]>dis+cnt){
                            dp[j][0]=dis+cnt;
                            q.push({dp[j][0],j,0});
                        }
                        cnt++;
                    }
                    cnt=0;
                    for(int j=i;j>=0;j-=bc){
                        if(dp[j][0]>dis+cnt){
                            dp[j][0]=dis+cnt;
                            q.push({dp[j][0],j,0});
                        }
                        cnt++;
                    }
                }
            }
        }
        else{
            if(i+pk<n && dp[i+pk][pk]>dis+1){
                dp[i+pk][pk]=dis+1;
                q.push({dp[i+pk][pk],i+pk,pk});
            }
            if(i-pk>=0 && dp[i-pk][pk]>dis+1){
                dp[i-pk][pk]=dis+1;
                q.push({dp[i-pk][pk],i-pk,pk});
            }
            if(dp[i][0]>dis){
                dp[i][0]=dis;
                q.push({dis,i,0});
            }
        }
    }
    cout << (ans!=1e9 ? ans:-1);
}

int main()
{
    open_file();
    fast();
    input();
    NGU();
}
/*
1 2 5 7 7
*/

Compilation message (stderr)

skyscraper.cpp: In function 'void open_file()':
skyscraper.cpp:21:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:22:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 43 / 43