[CSP-S Simulation Test]: The maximum and XOR (math)

Topic Portal (internal title 81)

---

Input Format

　　A first line integer $ T (T \ leqslant 20) $, the test data set represents
　　the next $ T $ group, for each group, a first row of n-$ $ integer
　　second row has n-$ $ integer, It is $ w_1, w_2 ... w_n $
　　next $ n-1 $ lines of two integers $ x, y $, indicates there is a connection between the edge and $ X $ $ $ Y

---

Output Format

　　For each group, the answer is only one line, if small wins $ Q $ output $ Q $, $ T $ small wins $ T $ output, if the output tie $ D $.

---

Sample

Sample input:

2
3
2 2 2
1 2
1 3
4
7 1 4 2
1 2
1 3
2 4

Sample output:

Do
D

---

Data range and tips

Sample explained:

In the first group, the small $ Q $ select any node with a score of $ 2 $, $ T $ small remaining two selected nodes, the score is $ 0 $, $ Q $ small win
in the second set, the small $ Q $ The best and only small $ T $ draw, so the output of $ D $

data range:

For $ 30 \% $ data, $ n \ leqslant 20 $
to 100 $ \% $ data, $ n \ leqslant 100,000, w_i \ leqslant 10 ^ 9 $.

---

answer

Small $ Q $ certainly can not lose, a draw situation if and only if all of the $ w_i $ XOR and $ 0 $ can occur when, or $ Q $ small must not win.

Because the topic of people out of this problem is intended to get points, so there may be a variety of wrong answers to this question can be (heard on the beat can only withstood $ 6,7 $-point fake $ DP $'ll get $ 90 $ points) ......

Time complexity: $ \ Theta (T \ times n) $.

Expectations score: $ 100 $ points.

Actual score: $ 100 $ points.

---

Code time

#include<bits/stdc++.h>
using namespace std;
int n;
int w;
int XOR;
int main()
{
	int T;scanf("%d",&T);
	while(T--)
	{
		scanf("%d",&n);XOR=0;
		for(int i=1;i<=n;i++)
		{
			scanf("%d",&w);
			XOR^=w;
		}
		for(int i=1;i<n;i++)
			scanf("%d%d",&w,&w);
		if(XOR)puts("Q");
		else puts("D");
	}
	return 0;
}

---

rp++