oj.uz

Submission #25765

# Submission time Handle Problem Language Result Execution time Memory
25765 2017-06-24T05:35:03 Z 김동현(#1079) 전압 (JOI14_voltage) C++14
100 / 100
 316 ms 22672 KB 
#include <bits/stdc++.h>
using namespace std;

struct E{ int x, i; };

int n, m, vis[100010], cr, d[100010], ps[100010], pe[100010], cnt, dc, fl, ans;
vector<E> e[100010];
vector<int> t[100010];

void T_T(){ puts("0"); exit(0); }

void col(int x, int c){
	vis[x] = c;
	for(auto &i : e[x]){
		if(vis[i.x] && vis[i.x] != 3 - c) fl = 0;
		else if(!vis[i.x]) col(i.x, 3 - c);
	}
}

const int sz = 131072;
struct Seg{
	int dat[2 * sz];
	void upd(int x, int v){ for(x += sz; x; x /= 2) dat[x] += v; }
	int get(int s, int e){
		int ret = 0;
		for(s += sz, e += sz; s <= e; s /= 2, e /= 2){
			if(s % 2 == 1) ret += dat[s++];
			if(e % 2 == 0) ret += dat[e--];
		}
		return ret;
	}
} S[2];

void g(int x, int p){
	vis[x] = 1;
	ps[x] = ++cnt;
	for(auto &i : e[x]){
		if(i.i == p) continue;
		if(vis[i.x] && d[i.x] < d[x]){
			int t = (d[i.x] + d[x]) & 1;
			//printf("back %d - %d : %d\n", x, i.x, t);
			if(!t) dc++;
			S[t].upd(ps[i.x], -1);
			S[t].upd(ps[x], 1);
		}
		else if(!vis[i.x]){
			//printf("go %d -> %d\n", x, i.x);
			t[x].push_back(i.x);
			d[i.x] = d[x] + 1;
			g(i.x, i.i);
		}
	}
	pe[x] = cnt;
}

void f(int x){
	for(auto &i : t[x]){
		f(i);
		int t0 = S[0].get(ps[i], pe[i]);
		int t1 = S[1].get(ps[i], pe[i]);
		//printf("%d -> %d : %d / %d\n", x, i, t0, t1);
		if(t0 == dc && !t1) ans++;
	}
}

int main(){
	scanf("%d%d", &n, &m);
	for(int i = 0, x, y; i < m; i++){
		scanf("%d%d", &x, &y);
		e[x].push_back({y, i});
		e[y].push_back({x, i});
	}
	for(int i = 1; i <= n; i++){
		if(!vis[i]){
			fl = 1;
			col(i, 1);
			if(!fl){
				if(cr) T_T();
				cr = i;
			}
		}
	}
	fill(vis + 1, vis + n + 1, 0);
	if(!cr){
		int rans = 0;
		for(int i = 1; i <= n; i++){
			if(vis[i]) continue;
			ans = dc = 0;
			g(i, -1);
			if(dc > 1) ans = 0;
			else if(dc == 1) ans = 1;
			f(i);
			rans += ans;
		}
		printf("%d\n", rans);
	}
	else{
		g(cr, -1);
		if(dc > 1) ans = 0;
		else if(dc == 1) ans = 1;
		f(cr);
		printf("%d\n", ans);
	}
}

Compilation message

voltage.cpp: In function 'int main()':
voltage.cpp:67:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
                       ^
voltage.cpp:69:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &x, &y);
                        ^

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 10452 KB Output is correct
2 Correct 0 ms 10320 KB Output is correct
3 Correct 0 ms 10460 KB Output is correct
4 Correct 0 ms 10452 KB Output is correct
5 Correct 3 ms 10452 KB Output is correct
6 Correct 0 ms 10452 KB Output is correct
7 Correct 0 ms 10452 KB Output is correct
8 Correct 3 ms 10452 KB Output is correct
9 Correct 3 ms 10452 KB Output is correct
10 Correct 0 ms 10452 KB Output is correct
11 Correct 0 ms 10452 KB Output is correct
12 Correct 0 ms 10452 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 66 ms 15572 KB Output is correct
2 Correct 196 ms 19104 KB Output is correct
3 Correct 66 ms 15572 KB Output is correct
4 Correct 166 ms 20080 KB Output is correct
5 Correct 9 ms 11008 KB Output is correct
6 Correct 166 ms 17124 KB Output is correct
7 Correct 166 ms 21084 KB Output is correct
8 Correct 173 ms 21088 KB Output is correct

Subtask #3
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 43 ms 15572 KB Output is correct
2 Correct 73 ms 21088 KB Output is correct
3 Correct 69 ms 21088 KB Output is correct
4 Correct 0 ms 10320 KB Output is correct
5 Correct 139 ms 17280 KB Output is correct
6 Correct 149 ms 15732 KB Output is correct
7 Correct 179 ms 18248 KB Output is correct
8 Correct 216 ms 19540 KB Output is correct
9 Correct 193 ms 19056 KB Output is correct
10 Correct 176 ms 18048 KB Output is correct
11 Correct 133 ms 15732 KB Output is correct
12 Correct 173 ms 17336 KB Output is correct

Subtask #4
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 16596 KB Output is correct
2 Correct 133 ms 22672 KB Output is correct
3 Correct 0 ms 10320 KB Output is correct
4 Correct 179 ms 18860 KB Output is correct
5 Correct 186 ms 19632 KB Output is correct
6 Correct 196 ms 18740 KB Output is correct
7 Correct 306 ms 20564 KB Output is correct
8 Correct 176 ms 21212 KB Output is correct
9 Correct 316 ms 19600 KB Output is correct
10 Correct 259 ms 21396 KB Output is correct
11 Correct 243 ms 19212 KB Output is correct
12 Correct 246 ms 21540 KB Output is correct
13 Correct 219 ms 17704 KB Output is correct
14 Correct 269 ms 21900 KB Output is correct
15 Correct 223 ms 21436 KB Output is correct
16 Correct 279 ms 21004 KB Output is correct
17 Correct 303 ms 18948 KB Output is correct
18 Correct 193 ms 19440 KB Output is correct