Submission #43579

#	Time	Username	Problem	Language	Result	Execution time	Memory
43579		RezwanArefin01	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	307 ms	78924 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> ii; 

const int maxn = 30000;

int n, m, b[maxn], p[maxn], dist[maxn];
set<int> st[maxn];
vector<int> adj[maxn], cost[maxn];

void addedge(int u, int v, int c) {
	adj[u].push_back(v);
	cost[u].push_back(c);
}

int main(int argc, char const *argv[]) {
#ifdef LOCAL_TESTING
	freopen("in", "r", stdin);
#endif
	int ans = 0;
	scanf("%d %d", &n, &m);

	for(int i = 0; i < m; i++) {
		scanf("%d %d", &b[i], &p[i]); 
		st[b[i]].insert(p[i]);
	}	

	for(int pos = 0; pos < n; pos++) {
		for(int p : st[pos]) {
			for(int i = 1; ; i++) {
				int nxt = pos + i * p;
				if(nxt < n) {
					addedge(pos, nxt, i);
					if(st[nxt].find(p) != st[nxt].end()) break;
				} else break;
			}
			for(int i = 1; ; i++) {
				int nxt = pos - i * p; 
				if(nxt >= 0) {
					addedge(pos, nxt, i);
					if(st[nxt].find(p) != st[nxt].end()) break;
				} else break;
			}
		}
	}

	priority_queue<ii, vector<ii>, greater<ii> > q;
	memset(dist, 63, sizeof dist); 
	q.push({dist[b[0]] = 0, b[0]});

	while(!q.empty()) {
		ii x = q.top(); q.pop();
		int u = x.second, w = x.first;
		for(int i = 0; i < adj[u].size(); i++) {
			int v = adj[u][i], c = cost[u][i];
			if(dist[v] > w + c) {
				dist[v] = w + c;
				q.push({dist[v], v});
			}
		}
	}

	if(dist[b[1]] >= 1e8) puts("-1");
	else cout << dist[b[1]] << endl;

}

Compilation message (stderr)

skyscraper.cpp: In function 'int main(int, const char**)':
skyscraper.cpp:56:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < adj[u].size(); i++) {
                    ^
skyscraper.cpp:22:6: warning: unused variable 'ans' [-Wunused-variable]
  int ans = 0;
      ^
skyscraper.cpp:23:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
                        ^
skyscraper.cpp:26:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &b[i], &p[i]); 
                               ^

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