| ❗ This is very important, consider the next points since the task provided, on my point of view, had typing errors, so it was needed to update the config file |
|---|
for the first example the matrix and the calculations are not matching Calculations: (bet_amount x reward(symbol_A) x reward(same_symbol_5_times) x reward(same_symbols_vertically)) + ( bet_amount x reward(symbol_B) x reward(same_symbol_3_times) x reward(same_symbols_vertically)) (+/x) reward(+1000) = ( 100 x5 x5 x2) + (100 x3 x1 x2) +1000 = 5000 + 600 + 1000 = 6600 reward(symbol_A), according the config file should be x50 reward(symbol_B), according the config file should be x25
for the third example the matrix and the calculations are not matching
Formula: 100(betting amount) x 25(symbol B) x2(at least 3 same symbols winning combination) x10(x10 bonus symbol) = 50000 (winning amount) x2(at least 3 same symbols winning combination), according the config file should be x1
same_symbols_horizontally ["1:0", "1:1", "1:1"], it seems should be ["1:0", "1:1", "1:2"],
since "same_symbols_vertically" does not have "reward_multiplier" the default value will be zero
- JDK >= 1.8
- Maven or Gradle
- feel free to choose any libraries for serialize/deserialize JSON and testing
- not recommended to add any additional libraries/frameworks, like spring or other high level frameworks
Problem statement: You need to build a scratch game, that will generate a matrix (for example 3x3) from symbols(based on probabilities for each individual cell) and based on winning combintations user either will win or lost. User will place a bet with any amount which we call betting amount in this assignment.
There are two types of symbols: Standard Symbols, Bonus Symbols.
Standard Symbols: identifies if user won or lost the game based on winning combinations (combination can be X times repeated symbols or symbols that follow a specific pattern) Bonus symbols are described the table below:
| Symbol Name | Reward Multiplier |
|---|---|
| A | 50 |
| B | 25 |
| C | 10 |
| D | 5 |
| E | 3 |
| F | 1.5 |
Bonus Symbols: Bonus symbols are only effective when there are at least one winning combinations matches with the generated matrix. Bonus symbols are described the table below:
| Symbol Name | Action |
|---|---|
| 10x | mutiply final reward to 10 |
| 5x | mutiply final reward to 5 |
| +1000 | add 1000 to the final reward |
| +500 | add 500 to the final reward |
| MISS | none |
Let's look at the configuration file below:
{
"columns": 3,
// OPTIONAL
"rows": 3,
// OPTIONAL
"symbols": {
"A": {
"reward_multiplier": 50,
"type": "standard"
},
"B": {
"reward_multiplier": 25,
"type": "standard"
},
"C": {
"reward_multiplier": 10,
"type": "standard"
},
"D": {
"reward_multiplier": 5,
"type": "standard"
},
"E": {
"reward_multiplier": 3,
"type": "standard"
},
"F": {
"reward_multiplier": 1.5,
"type": "standard"
},
"10x": {
"reward_multiplier": 10,
"type": "bonus",
"impact": "multiply_reward"
},
"5x": {
"reward_multiplier": 5,
"type": "bonus",
"impact": "multiply_reward"
},
"+1000": {
"extra": 1000,
"type": "bonus",
"impact": "extra_bonus"
},
"+500": {
"extra": 500,
"type": "bonus",
"impact": "extra_bonus"
},
"MISS": {
"type": "bonus",
"impact": "miss"
}
},
"probabilities": {
"standard_symbols": [
{
"column": 0,
"row": 0,
"symbols": {
"A": 1,
"B": 2,
"C": 3,
"D": 4,
"E": 5,
"F": 6
}
},
{
"column": 0,
"row": 1,
"symbols": {
"A": 1,
"B": 2,
"C": 3,
"D": 4,
"E": 5,
"F": 6
}
}
//...
],
"bonus_symbols": {
"symbols": {
"10x": 1,
"5x": 2,
"+1000": 3,
"+500": 4,
"MISS": 5
}
}
},
"win_combinations": {
"same_symbol_3_times": {
"reward_multiplier": 1,
"when": "same_symbols",
"count": 3,
"group": "same_symbols"
},
"same_symbol_4_times": {
"reward_multiplier": 1.5,
"when": "same_symbols",
"count": 4,
"group": "same_symbols"
},
"same_symbol_5_times": {
"reward_multiplier": 2,
"when": "same_symbols",
"count": 5,
"group": "same_symbols"
},
"same_symbol_6_times": {
"reward_multiplier": 3,
"when": "same_symbols",
"count": 6,
"group": "same_symbols"
},
"same_symbol_7_times": {
"reward_multiplier": 5,
"when": "same_symbols",
"count": 7,
"group": "same_symbols"
},
"same_symbol_8_times": {
"reward_multiplier": 10,
"when": "same_symbols",
"count": 8,
"group": "same_symbols"
},
"same_symbol_9_times": {
"reward_multiplier": 20,
"when": "same_symbols",
"count": 9,
"group": "same_symbols"
},
"same_symbols_horizontally": {
// OPTIONAL
"reward_multiplier": 2,
"when": "linear_symbols",
"group": "horizontally_linear_symbols",
"covered_areas": [
[
"0:0",
"0:1",
"0:2"
],
[
"1:0",
"1:1",
"1:1"
],
[
"2:0",
"2:1",
"2:2"
]
]
},
"same_symbols_vertically": {
// OPTIONAL
"reward_multiplier": 2,
"when": "linear_symbols",
"group": "vertically_linear_symbols",
"covered_areas": [
[
"0:0",
"1:0",
"2:0"
],
[
"0:1",
"1:1",
"2:1"
],
[
"0:2",
"1:2",
"2:2"
]
]
},
"same_symbols_diagonally_left_to_right": {
// OPTIONAL
"reward_multiplier": 5,
"when": "linear_symbols",
"group": "ltr_diagonally_linear_symbols",
"covered_areas": [
[
"0:0",
"1:1",
"2:2"
]
]
},
"same_symbols_diagonally_right_to_left": {
// OPTIONAL
"reward_multiplier": 5,
"when": "linear_symbols",
"group": "rtl_diagonally_linear_symbols",
"covered_areas": [
[
"0:2",
"1:1",
"2:0"
]
]
}
}
}| field name | description |
|---|---|
| columns | number of columns in the matrix |
| rows | number of rows in the matrix |
| symbols | list of symbols |
| symbol.{X}.reward_multiplier | will multiply betting amount |
| symbol.{X}.type | can be either standard or bonus |
| symbol.{X}.extra | [only for bonuses] extra amount which will be added to the reward |
| symbol.{X}.impact | [only for bonuses] fixed values: multiply_reward (which multiply final reward to symbol.{X}.reward_multiplier), extra_bonus(will add symbol.{X}.extra to the final reward), miss(nothing) |
| probabilities | list of probabilities |
| probabilities.standard_symbols | list of probabilities for standard symbols |
| probabilities.standard_symbols[...].column | column index |
| probabilities.standard_symbols[...].row | row index |
| probabilities.standard_symbols[...].symbols | map of a symbol and it's probability number(to calculate to probability percentage just sum all symbols probability numbers and divide individual symbol's probability number to total probability numbers) |
| probabilities.bonus_symbols | list of probabilities for bonus symbols |
| probabilities.bonus_symbols.symbols | map of a symbol and it's probability number(to calculate to probability percentage just sum all symbols probability numbers and divide individual symbol's probability number to total probability numbers) |
| probabilities.win_combinations | list of winning combinations |
| probabilities.win_combinations.{X}.reward_multiplier | will multiply reward |
| probabilities.win_combinations.{X}.count | required count of the same symbols to activate the reward |
| probabilities.win_combinations.{X}.group | group which the winning combination belongs to, max 1 winning combination should be applied for each win combination group |
| probabilities.win_combinations.{X}.covered_areas | array of array of strings which is described as "%d:%d" which demonstrates row and column number respectively |
| probabilities.win_combinations.{X}.when | fixed values: same_symbols (if one symbol repeated in the matrix probabilities.win_combinations.{X}.count times), linear_symbols(if it matches to probabilities.win_combinations.{X}.covered_areas) |
- Note: Fields which are marked as OPTIONAL, are not required but will add extra points to the candidate if the candidate implements it.
- Note (2): Bonus symbol can be generated randomly in any cell(s) in the matrix
- Note (3): If one symbols matches more than winning combinations then reward should be multiplied. formula: (SYMBOL_1 * WIN_COMBINATION_1_FOR_SYMBOL_1 * WIN_COMBINATION_2_FOR_SYMBOL_1)
- Note (4): If the more than one symbols matches any winning combinations then reward should be summed. formula: ( SYMBOL_1 * WIN_COMBINATION_1_FOR_SYMBOL_1 * WIN_COMBINATION_2_FOR_SYMBOL_1) + (SYMBOL_2 * WIN_COMBINATION_1_FOR_SYMBOL_2)
Input format:
"bet_amount": 100
| field name | description |
|---|---|
| bet_amount | betting amount |
Output format:
{
"matrix": [
[
"A",
"A",
"B"
],
[
"A",
"+1000",
"B"
],
[
"A",
"A",
"B"
]
],
"reward": 6600,
"applied_winning_combinations": {
"A": [
"same_symbol_5_times",
"same_symbols_vertically"
],
"B": [
"same_symbol_3_times",
"same_symbols_vertically"
]
},
"applied_bonus_symbol": "+1000"
}| field name | description |
|---|---|
| matrix | generated 2D matrix |
| reward | final reward which user won |
| applied_winning_combinations | Map of Symbol and List of applied winning combinations |
| applied_bonus_symbol | applied bonus symbol (can be null if the bonus is MISS |
Rewards breakdown:
| reward name | reward details |
|---|---|
| symbol_A | bet_amount x5 |
| symbol_B | bet_amount x3 |
| same_symbol_5_times | (reward for a specific symbol) x5 |
| same_symbol_3_times | (reward for a specific symbol) x1 |
| same_symbols_vertically | (reward for a specific symbol) x2 |
| +1000 | add 1000 extra to final reward |
Calculations: (bet_amount x reward(symbol_A) x reward(same_symbol_5_times) x reward(same_symbols_vertically)) + ( bet_amount x reward(symbol_B) x reward(same_symbol_3_times) x reward(same_symbols_vertically)) (+/x) reward(+1000) = ( 100 x5 x5 x2) + (100 x3 x1 x2) +1000 = 5000 + 600 + 1000 = 6600
Examples (with a winning combination [same symbols should be repeated at least 3 / reward x2]):
Lost game:
| input | output |
|---|---|
| "bet_amount": 100 | { "matrix": [ ["A", "B", "C"], ["E", "B", "5x"], ["F", "D", "C"] ], "reward": 0 } |
Description: The game is settled as LOST, so bonus symbol has not been applied because the reward is 0.
Won game:
| input | output |
|---|---|
| "bet_amount": 100 | { "matrix": [ ["A", "B", "C"], ["E", "B", "10x"], ["F", "D", "B"] ], "reward": 50000, "applied_winning_combinations": { "B": ["same_symbol_5_times"] }, "applied_bonus_symbol": "10x" } |
Description: user placed a bet with 100 betting amount and generated matrix has 3 same symbols which matches with the winning combination, also 10x bonus also will be applied. Formula: 100(betting amount) x 25(symbol B) x2(at least 3 same symbols winning combination) x10(x10 bonus symbol) = 50000 (winning amount)
Note: Please make sure there are no errors while building (all test cases should be passed if you provided any) and your solution is testable through CLI like below:
java -jar scratch-game-jar-with-dependencies.jar --config config.json --betting-amount 100| parameter | description |
|---|---|
| config | config file which is described top of the document |
| betting amount | betting amount |