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Submission #29295

# Submission time Handle Problem Language Result Execution time Memory
29295 2017-07-19T01:41:05 Z 김동현(#1164) Dynamite (POI11_dyn) C++14
100 / 100
 1976 ms 30400 KB 
#include <bits/stdc++.h>
using namespace std;

int n, m, d[300010], ans;
vector<int> e[300010];

int f(int x, int p, int c){
	int t = 0, v = 0;
	for(auto &i : e[x]){
		if(i != p){
			int u = f(i, x, c);
			if(!u) continue;
			if(u > 0) v = max(v, u);
			else t = min(t, u);
		}
	}
	if(abs(t) >= c){
		ans++;
		return c;
	}
	if(!v && !t) return -d[x];
	if(v > abs(t)) return v - 1;
	return t - 1;
}

int can(int k){
	ans = 0;
	if(f(1, 0, k) < 0) ans++;
	return ans <= m;
}

int main(){
	scanf("%d%d", &n, &m);
	for(int i = 1; i <= n; i++) scanf("%d", d + i);
	for(int i = 0, x, y; i < n - 1; i++){
		scanf("%d%d", &x, &y);
		e[x].push_back(y);
		e[y].push_back(x);
	}
	if(count(d + 1, d + n + 1, 1) <= m){ puts("0"); return 0; }
	int st = 1, en = n - 1;
	while(st <= en){
		int mi = (st + en) / 2;
		if(can(mi)) en = mi - 1;
		else st = mi + 1;
	}
	printf("%d\n", st);
}

Compilation message

dyn.cpp: In function 'int main()':
dyn.cpp:33:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
                       ^
dyn.cpp:34:48: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 1; i <= n; i++) scanf("%d", d + i);
                                                ^
dyn.cpp:36:24: 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 10224 KB Output is correct
2 Correct 0 ms 10224 KB Output is correct
3 Correct 3 ms 10224 KB Output is correct
4 Correct 0 ms 10224 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 10224 KB Output is correct
2 Correct 3 ms 10224 KB Output is correct
3 Correct 0 ms 10224 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 10224 KB Output is correct
2 Correct 3 ms 10224 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 10224 KB Output is correct
2 Correct 3 ms 10224 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 10620 KB Output is correct
2 Correct 39 ms 11016 KB Output is correct
3 Correct 39 ms 11148 KB Output is correct
4 Correct 63 ms 12760 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 63 ms 12072 KB Output is correct
2 Correct 159 ms 12600 KB Output is correct
3 Correct 309 ms 12732 KB Output is correct
4 Correct 246 ms 15620 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 166 ms 13656 KB Output is correct
2 Correct 129 ms 13660 KB Output is correct
3 Correct 459 ms 13392 KB Output is correct
4 Correct 199 ms 18300 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 843 ms 16692 KB Output is correct
2 Correct 376 ms 18156 KB Output is correct
3 Correct 866 ms 25328 KB Output is correct
4 Correct 1579 ms 25324 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1883 ms 22112 KB Output is correct
2 Correct 1186 ms 20536 KB Output is correct
3 Correct 1976 ms 24972 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1649 ms 28388 KB Output is correct
2 Correct 1279 ms 20540 KB Output is correct
3 Correct 1866 ms 30400 KB Output is correct
4 Correct 559 ms 21680 KB Output is correct