Sukat

input/code.cpp: In function 'int main()':
input/code.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     for (int i = 0; i < strlen(s); i++) {
      |                     ~~^~~~~~~~~~~
input/code.cpp:40:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<char, char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |     for (int i = 0; i < res.size(); i++) {
      |                     ~~^~~~~~~~~~~~
input/code.cpp:16:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     scanf("%s", s);
      |     ~~~~~^~~~~~~~~

#include <bits/stdc++.h>
using namespace std;

#define CHARS 26

int nums[CHARS];

int main()
{
    int n;
    cin >> n;

    vector<pair<char, char>> res;

    char s[200000];
    scanf("%s", s);
    for (int i = 0; i < strlen(s); i++) {
        char c = s[i];
        cerr << c << endl;

        int a = c - 'A';
        nums[a]++;
    }

    for (int i = 0; i < CHARS - 1; i++) {
        for (int j = i + 1; j < CHARS && nums[i] > 0; j++) {
            cerr << i << " " << j << endl;
            if (nums[j] == 0) {
                continue;
            }

            nums[i]--;
            nums[j]--;
            res.push_back(make_pair(i + 'A', j + 'A'));
        }
    }

    cout << res.size() << endl;

    for (int i = 0; i < res.size(); i++) {
        cout << res[i].first << res[i].second << endl;
    }
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Q
B
A
X
G
X
J
Z
J
S
0 1
6 7
6 8
6 9
9 10
9 11
9 12
9 13
9 14
9 15
9 16
18 19
18 20
18 21
1...

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

S
S
S
S
S
S
S
S
S
S
18 19
18 20
18 21
18 22
18 23
18 24
18 25

Test 3

Group: 1, 2, 3

Verdict: WRONG ANSWER

S
E
T
T
S
E
S
E
E
E
4 5
4 6
4 7
4 8
4 9
4 10
4 11
4 12
4 13
4 14
4 15
4 16
4 17
4 18
4 19...

Test 4

Group: 1, 2, 3

Verdict: WRONG ANSWER

S
S
M
R
S
S
S
S
K
R
10 11
10 12
17 18
17 19
17 20
17 21
17 22
17 23
17 24
17 25
18 19
18 2...

Test 5

Group: 1, 2, 3

Verdict: WRONG ANSWER

B
I
I
I
L
I
I
R
R
L
1 2
1 3
1 4
1 5
1 6
1 7
1 8
8 9
8 10
8 11
8 12
8 13
8 14
8 15
8 16
8 1...

Test 6

Group: 1, 2, 3

Verdict: WRONG ANSWER

Y
Y
G
E
Y
T
D
S
T
Y
3 4
6 7
6 8
6 9
6 10
6 11
6 12
6 13
6 14
6 15
6 16
6 17
6 18
19 20
19...

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

M
M
M
M
M
M
M
M
M
N
12 13
12 14
12 15
12 16
12 17
12 18
12 19
12 20
12 21
12 22
12 23
12 2...

Test 8

Group: 2, 3

Verdict: WRONG ANSWER

X
Q
Q
Z
J
Q
D
D
J
O
W
X
D
F
V
Q
U
I
O
D
D
J
I
Z
I
Q
D
Q
I
W
Q
Q
V
Q
O
D
I
Q
B
I
D
X
D
B
D...

Test 9

Group: 2, 3

Verdict: ACCEPTED

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I...

Test 10

Group: 2, 3

Verdict: WRONG ANSWER

K
E
O
H
H
Y
H
H
A
I
H
L
L
H
E
K
I
H
K
A
H
H
H
H
O
H
E
H
H
E
I
H
H
H
O
H
H
H
H
H
H
H
O
R
E...

Test 11

Group: 2, 3

Verdict: WRONG ANSWER

W
N
N
F
X
Q
N
O
D
Q
F
S
Q
V
Q
Q
P
N
L
Q
N
Q
N
N
V
V
N
X
H
N
N
R
Z
D
N
N
N
N
R
P
Q
R
N
N
R...

Test 12

Group: 2, 3

Verdict: WRONG ANSWER

V
G
A
H
M
M
M
X
M
M
V
X
A
A
M
M
M
O
M
M
M
X
V
M
M
M
Y
M
X
T
M
M
M
M
Q
M
U
M
M
P
M
M
M
V
M...

Test 13

Group: 2, 3

Verdict: WRONG ANSWER

K
K
K
K
U
U
A
K
K
A
U
K
K
K
K
F
K
K
S
V
K
C
W
K
K
K
C
V
O
J
C
Q
O
L
F
K
V
Z
U
K
K
K
O
D
S...

Test 14

Group: 2, 3

Verdict: WRONG ANSWER

V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
T
V
V
V
V...

Test 15

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 16

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 17

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 18

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 19

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 20

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 21

Group: 3

Verdict: TIME LIMIT EXCEEDED