Submission #155418

#	Time	Username	Problem	Language	Result	Execution time	Memory
155418		aer0park	Ideal city (IOI12_city)	C++14	100 / 100	61 ms	7544 KiB

city

#include <vector>
#include <algorithm>
using namespace std;

#define MAXN 100005
#define pb push_back
#define sz(v) ((int)(v).size())
#define connect(a,b) con[a].pb(b),con[b].pb(a)
typedef long long lld;

static const int MOD = 1e9;
static int N,M,ans;
static vector<int> con[MAXN];

static struct Z{
	int x,y;
	bool operator < (const Z &ot)const{
		return y!=ot.y?y<ot.y:x<ot.x;
	}
} A[MAXN];

static struct NODE{
	int y,x1,x2;
} T[MAXN];

int dfs(int n,int par)
{
	int size=T[n].x2-T[n].x1+1,i,k;
	for (i=sz(con[n]);i--;){
		k = con[n][i];
		if (par == k) continue;
		size += dfs(k,n);
	}
	ans = (ans+(lld)size*(N-size))%MOD;
	return size;
}

void proc()
{
	int i,j,s,e;
	sort(A+1,A+N+1); M = 0;
	for (i=j=1;i<=N;i++){
		if (i == N || A[i].y != A[i+1].y || A[i].y == A[i+1].y && A[i].x+1 < A[i+1].x){
			T[++M].y = A[i].y;
			T[M].x1 = A[j].x;
			T[M].x2 = A[i].x;
			j = i+1;
		}
	}
	for (i=1;i<=M;i++) con[i].clear();
	for (i=1,s=e=2;i<=M;i++){
		while (e <= M && (T[e].y <= T[i].y || T[e].y == T[i].y+1 && T[e].x1 <= T[i].x2)) e++;
		while (s <= M && (T[s].y <= T[i].y || T[s].y == T[i].y+1 && T[s].x2 < T[i].x1)) s++;
		for (j=s;j<e;j++) connect(i,j);
	}
	dfs(1,0);
}

int DistanceSum(int n, int *x, int *y)
{
	int i;
	N = n;
	for (i=1;i<=N;i++) A[i].x = x[i-1], A[i].y = y[i-1];
	proc();
	for (i=1;i<=N;i++) swap(A[i].x,A[i].y);
	proc();
	return ans;
}

Compilation message (stderr)

city.cpp: In function 'void proc()':
city.cpp:43:58: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if (i == N || A[i].y != A[i+1].y || A[i].y == A[i+1].y && A[i].x+1 < A[i+1].x){
                                       ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
city.cpp:52:60: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   while (e <= M && (T[e].y <= T[i].y || T[e].y == T[i].y+1 && T[e].x1 <= T[i].x2)) e++;
                                         ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
city.cpp:53:60: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   while (s <= M && (T[s].y <= T[i].y || T[s].y == T[i].y+1 && T[s].x2 < T[i].x1)) s++;
                                         ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 45 / 45