Codeforces/yetanothertetrisproblem.cpp at master · rage73/Codeforces · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
#include<bits/stdc++.h>
using namespace std;
// https://codeforces.com/contest/1324/problem/A

typedef long long ll;

bool areAllOdd(int a[],int n)
{
    for(int i=0;i<n;i++)
    {
        if(a[i]%2==0 and a[i]!=0)
        {
            return false;
        }
    }
    return true;
}

bool arePositive(int a[],int n)
{
    for(int i=0;i<n;i++)
    {
        if(a[i]<=0)
        {
            return false;
        }
    }
    return true;
}

bool areAllEqual(int a[],int n)
{
    for(int i=1;i<n;i++)
    {
        if(a[i]!=a[0])
        {
            return false;
        }
    }
    return true;
}

int smallestIdx(int a[],int n)
{
    int idx=0;
    for(int i=1;i<n;i++)
    {
        if(a[i]<a[idx])
        {
            idx=i;
        }
    }
    return idx;
}

bool canClear(int a[],int n)
{
    if(n<=1 or areAllEqual(a,n))
    {
        return true;
    }
    int small=smallestIdx(a,n);
    a[small]+=2;
    small=smallestIdx(a,n);
    int diff=a[small];
    for(int i=0;i<n;i++)
    {
        a[i]-=diff;
    }
    while(!arePositive(a,n))
    {
        int small=smallestIdx(a,n);
        a[small]+=2;
    }
    small=smallestIdx(a,n);
    diff=a[small];
    for(int i=0;i<n;i++)
    {
        a[i]-=diff;
    }
    if(areAllEqual(a,n))
    {
        return true;
    }
    if(areAllOdd(a,n))
    {
        return false;
    }
    return canClear(a,n);
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        int a[n];
        for(int i=0;i<n;i++)
        {
            cin>>a[i];
        }
        cout<<(canClear(a,n)?"YES":"NO")<<endl;
    }
    return 0;
}