problem from contest

Zaikia and sticks Problem Code: CKOJ20A   

 

Zaikia has N$N$ sticks of distinct positive lengths A1,A2,…,AN$A_1,A_2,\dots ,A_N$. For no good reason at all, he wants to know if there is a triplet of sticks which when connected end-to-end will form a non-trivial triangle. Here non-trivial refers to a triangle with positive area.

Help Zaikia know if such a triplet exists or not. If such a triplet exists, help him find the lexicographically largest applicable triplet.

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Input

• The first line contains an integer N$N$.
• The second line contains N$N$ space-seperated integers A1,A2,…,AN$A_1,A_2,\dots ,A_N$.

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Output

• In the first line print YES if a triplet exists or NO if it doesn't.
• If such a triplet exists, then in the second line print the lexicographically largest applicable triplet.

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Constraints

• 3≤N≤2×105$3\le N\le 2\times {10}^5$
• 1≤Ai≤109$1\le A_i\le {10}^9$ for each valid i$i$

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Sample Input 1

5
4 2 10 3 5

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Sample Output 1

YES
5 4 3

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Explanation 1

There are three unordered triplets of sticks which can be used to create a triangle:

• 4,2,3$4,2,3$
• 4,2,5$4,2,5$
• 4,3,5$4,3,5$

Arranging them in lexicographically largest fashion

• 4,3,2$4,3,2$
• 5,4,2$5,4,2$
• 5,4,3$5,4,3$

Here 5,4,3$5,4,3$ is the lexicographically largest so it is the triplet which dristiron wants

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Sample Input 2

5
1 2 4 8 16

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Sample Output 2

NO

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Explanation 2

There are no triplets of sticks here that can be used to create a triangle.

1

#include <bits/stdc++.h>

using namespace std;

const int N = 200010;

int n, a[N];

int main() {
  cin >> n;
  for (int i = 1; i <= n; ++i) scanf("%d", a + i);
  sort(a + 1, a + n + 1);
  for (int i = n; i >= 3; --i) {
    if (a[i - 1] + a[i - 2] > a[i]) {
      puts("YES");
      printf("%d %d %d\n", a[i], a[i - 1], a[i - 2]);
      return 0;
    }
  }
  puts("NO");
  return 0;
}

2.

n = int(input())

a = list(map(int,input().split()))

a.sort()

i=n-3

ans = []

tmp=0

while(i>=0):

    if a[i]+a[i+1]>a[i+2]:

        print("YES")

        print(a[i+2],a[i+1],a[i])

        tmp=1

        break

    i-=1

if tmp==0:

    print("NO")

# sabse pahle arr ko sort kr diya aur last se check krna shuru kiya ,

kyu ki arr sort hai jo sabse pahle condtion satisfied krega wahi ans hoga

kuchh nhi milega to 'NO' print kr diya

(sare triplet nikalne ki jarurat nhi hai )

               Even-tual Reduction Problem Code: EVENTUAL 

Read problems statements in Hindi, Mandarin Chinese, Russian, Vietnamese, and Bengali as well.

You are given a string S

with length N. You may perform the following operation any number of times: choose a non-empty substring of S (possibly the whole string S) such that each character occurs an even number of times in this substring and erase this substring from S. (The parts of S

before and after the erased substring are concatenated and the next operation is performed on this shorter string.)

For example, from the string "acabbad", we can erase the highlighted substring "abba", since each character occurs an even number of times in this substring. After this operation, the remaining string is "acd".

Is it possible to erase the whole string using one or more operations?

Note: A string B

is a substring of a string A if B can be obtained from A

by deleting several (possibly none or all) characters from the beginning and several (possibly none or all) characters from the end.

Input

• The first line of the input contains a single integer T

denoting the number of test cases. The description of T

test cases follows.

The first line of each test case contains a single integer N

.

The second line contains a single string S

with length N

• .

Output

For each test case, print a single line containing the string "YES" if it is possible to erase the whole string or "NO" otherwise (without quotes).

Constraints

• 1≤T≤200

1≤N≤1,000

S

• contains only lowercase English letters

Example Input

4
6
cabbac
7
acabbad
18
fbedfcbdaebaaceeba
21
yourcrushlovesyouback

Example Output

YES
NO
YES
NO

Explanation

Example case 1: We can perform two operations: erase the substring "abba", which leaves us with the string "cc", and then erase "cc".

1.

for i in range(int(input())):

    n=int(input())

    s=input()

    dict_s={}

    for item in s:

        if (item in dict_s):

            dict_s[item]+=1 

        else:

            dict_s[item]=1

    flag=1

    for key in dict_s:

        if(dict_s[key]%2!=0):

            print('NO')

            flag=0

            break

    if(flag):

        print('YES')

        

2.

# cook your dish here

x=int(input())

while(x):

    x-=1

    n=int(input())

    s=input()

    s1=set(s) 

    #if n%2!=0:

        #flag="NO"

        #break

    for i in s1:

        if s.count(i)%2!=0:

            flag="NO"

            break

        else:

            flag="YES"

    print(flag)