---
id: 6a22d77ddf034bc4e35b1d54
title: "Challenge 347: Game Theory"
challengeType: 29
dashedName: challenge-347
---

# --description--

Given two equal length strings representing two players' strategies for a game, return the scores as an array `[player1, player2]`.

- The given strings will only contain one of two letters: `"C"` (cooperate) or `"D"` (defect).
- Each character represents one round, scored as follows:
  - If both players cooperate, each scores 3.
  - If both players defect, each scores 1.
  - If one player defects and the other cooperates, the defector scores 5 and the cooperator scores 0.

# --hints--

`play_game("CCCC", "CCCC")` should return `[12, 12]`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(play_game("CCCC", "CCCC"), [12, 12])`)
}})
```

`play_game("DDDD", "DDDD")` should return `[4, 4]`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(play_game("DDDD", "DDDD"), [4, 4])`)
}})
```

`play_game("CCDD", "CDDD")` should return `[5, 10]`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(play_game("CCDD", "CDDD"), [5, 10])`)
}})
```

`play_game("CCCDCDCCCDDC", "CCDDCDCDDCCD")` should return `[24, 34]`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(play_game("CCCDCDCCCDDC", "CCDDCDCDDCCD"), [24, 34])`)
}})
```

`play_game("DDCCDDDDCDDCDDDCDD", "CCDCCCDCCCDCCCCDCC")` should return `[66, 21]`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(play_game("DDCCDDDDCDDCDDDCDD", "CCDCCCDCCCDCCCCDCC"), [66, 21])`)
}})
```

# --seed--

## --seed-contents--

```py
def play_game(p1, p2):

    return p1
```

# --solutions--

```py
def play_game(p1, p2):
    scores = [0, 0]
    for i in range(len(p1)):
        if p1[i] == 'C' and p2[i] == 'C':
            scores[0] += 3
            scores[1] += 3
        elif p1[i] == 'D' and p2[i] == 'D':
            scores[0] += 1
            scores[1] += 1
        elif p1[i] == 'D' and p2[i] == 'C':
            scores[0] += 5
        else:
            scores[1] += 5
    return scores
```