Submission #121963

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
121963	2019-06-27T09:52:25 Z	turbat	Flood (IOI07_flood)	C++14	Compilation error	0 ms	0 KB

flood

    #include <bits/stdc++.h>
    using namespace std;
    #define F first
    #define S second
    #define N 100005
     
    int n, w, k, cnt;
    pair <int, int> wall[N][4];
    pair <pair <int, int>, int > p[N];
    bool vis[2 * N], brok[2 * N], stacked[N];
     
    int dfs(int dir, int u){
    	if (stacked[u]) return u;
    	stacked[u] = 1;
    	int t = dir + 3;
    	t %= 4;
    	while (t != (dir + 2) % 4){
    		if (!vis[wall[u][t].S]) {
    			vis[wall[u][t].S] = 1;
    			int cyc = dfs(t, wall[u][t].F);
    			if (cyc != -1){
    				brok[wall[u][t].S] = 1;
    				cnt--;
    				stacked[u] = 0;
    				if (cyc != u) return cyc;
    			}
    		}
    		t++;
    		t %= 4;
    	}
    	stacked[u] = 0;
    	return -1;
    }
     
    int main (){
    	vis[0] = 1;
    	cin >> n;
    	for (int i = 1;i <= n;i++) {
    		p[i].S = i;
    		cin >> p[i].F.F >> p[i].F.S;
    		pos[i] = p[i].F;
    	}
    	cin >> w;
    	for (int i = 1;i <= w;i++){
    		int a, b;
    		cin >> a >> b;
    		if (p[a] > p[b]) swap(a, b);
    		if (p[a].F.F == p[b].F.F){
    			wall[a][2].F = b, wall[b][0].F = a;
    			wall[a][2].S = wall[b][0].S = i;
    		}
    		else {
    			wall[a][1].F = b, wall[b][3].F = a;
    			wall[a][1].S = wall[b][3].S = i;
    		}
    	}
    	sort (p + 1, p + n + 1);
    	for (int i = 1;i <= n;i++) dfs(1, p[i].S);
    	cout << w - k<< endl;
    	for (int i = 1;i <= w;i++)
    		if (!brok[i])
    			cout << i << endl;
    }

Compilation message

flood.cpp: In function 'int main()':
flood.cpp:41:7: error: 'pos' was not declared in this scope
       pos[i] = p[i].F;
       ^~~
flood.cpp:41:7: note: suggested alternative: 'pow'
       pos[i] = p[i].F;
       ^~~
       pow