Submission #847631

#	Time	Username	Problem	Language	Result	Execution time	Memory
847631		Qiroz167	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	743 ms	17144 KiB

skyscraper

#include <bits/stdc++.h>
#define quan160607 "BoundSeq"
#define fi first
#define se second
#define pii pair<int, int>
#define piii pair<int, pii>
#define pb push_back
using namespace std;
typedef long long ll;
const ll oo = 1e18;
const int inf = 2e9;
const int nmax = 3e4 + 5;
void start()
{
//    freopen(quan160607".inp","r",stdin);
//    freopen(quan160607".out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int n, m;
int b[nmax], a[nmax], p[nmax];
vector<int> v[nmax];
const int block = 100;
int dp[nmax][block + 5];

struct gt
{
    int dis, u, p;
};

bool operator > (gt a, gt b)
{
    return a.dis > b.dis;
}
priority_queue<gt, vector<gt>, greater<gt>> q;

bool minimize(int &a, int b)
{
    if(a > b)
    {
        a = b;
        return true;
    } else return false;
}

int cnt;
int ans = inf;
void solve_dij()
{
    for(int i = 0; i <= n; i++)
    {
        for(int j = 0; j <= block; j++)
            dp[i][j] = inf;
    }
    dp[b[0]][0] = 0;
    q.push({dp[b[0]][0], b[0], 0});
    while(!q.empty())
    {
        gt temp = q.top();
        q.pop();
        int dis = temp.dis, u = temp.u, pk = temp.p;
        if(u == b[1]) ans = min(ans, dp[u][pk]);
        if(dis != dp[u][pk])
            continue;
        dp[u][0] = min(dp[u][0], dp[u][pk]);
        if(pk > 0) // true
        {
            if(u - pk >= 0) {
                if(minimize(dp[u - pk][pk], dp[u][pk] + 1))
                    q.push({dp[u - pk][pk], u - pk, pk});
                }
            if(u + pk < n) {
                if(minimize(dp[u + pk][pk], dp[u][pk] + 1))
                    q.push({dp[u + pk][pk], u + pk, pk});
            }
        }
        for(auto x : v[u])
        {
            if(x > block)
            {
                //dp[u][x]
                cnt = 0;
                for(int i = u; i < n; i += x) {
                    if(minimize(dp[i][0], dp[u][0] + cnt)) {
                        q.push({dp[i][0], i, 0});
                    }
                    cnt++;
                }
                cnt = 0;
                for(int i = u; i >= 0; i -= x) {
                    if(minimize(dp[i][0], dp[u][0] + cnt)) {
                        q.push({dp[i][0], i, 0});
                    }
                    cnt++;
                }
            }
            else {
                if(u - x >= 0) {
                    if(minimize(dp[u - x][x], dp[u][0] + 1))
                        q.push({dp[u - x][x], u - x, x});
                }
                if(u + x < n) {
                    if(minimize(dp[u + x][x], dp[u][0] + 1))
                        q.push({dp[u + x][x], u + x, x});
                }
            }
        }
    }
}
int main()
{
    start();
    cin >> n >> m;
    for(int i = 0; i < m; i++)
    {
        cin >> b[i] >> p[i];
        v[b[i]].push_back(p[i]);
    }
    solve_dij();
    cout << (ans == inf ? -1 : ans);
//    cout << "\n";
//    cout << dp[2][0] << " " << dp[2][1];
}

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