Thanks for taking the time to complete this task. The task is a real world problem, trying to see how you translate business requirements into readable, maintainable code.
A boilerplate is provided in src/main.rs to guide you through the development.
Take a look at comments to understand what you need to do.
Feel free to define new types if needed.
Implement calculate_balance_changes with the requirements mentioned in the comment of the function.
Here is an example that with the given input, the provided output must be the output of the function.
Example 1 (No issuer on sender or receiver)
original_balances [
"account1" = {
"denom1":1000_000
}
"account2": {
"denom2": 1000_000
}
]
definitions = [
{
denom: "denom1",
issuer: "issuer_account_A",
burn_rate: 0.08,
commission_rate: 0.12,
}
{
denom: "denom2",
issuer: "issuer_account_B",
burn_rate: 1,
commission_rate: 0,
}
]
multi_send = {
inputs = [
{
address: "account1"
coins: [
{
"denom1": 1000
}
]
}
{
address: "account2"
coins: [
{
"denom2": 1000
}
]
}
]
outputs = [
{
address: "account_recipient"
coins: [
{
"denom1": 1000
"denom2": 1000
}
]
}
]
}
the output of the function will be:
balance_changes = [
{
address: "account_recipient"
coins: [
{
"denom1": 1000
"denom2": 1000
}
]
}
{
address: "issuer_account_A"
coins: [
{
"denom1": 120
}
]
}
{
address: "account1"
coins: [
{
"denom1": -1200 // (1000 sent, 80 burnt, 120 send to issuer as commission)
}
]
}
{
address: "account2"
coins: [
{
"denom2": -2000 // (1000 sent and 1000 burnt(burn_rate is 1))
}
]
}
]
Example 2 (issuer exists on sender/receiver)
original_balances [
"account1" = {
"denom1":1000_000
}
"account2" = {
"denom1":1000_000
}
]
definitions = [
{
denom: "denom1",
issuer: "issuer_account_A",
burn_rate: 0.08,
commission_rate: 0.12,
}
]
multi_send = {
inputs = [
{
address: "account1"
coins: [
{
"denom1": 650
}
]
}
{
address: "account2"
coins: [
{
"denom1": 350
}
]
}
]
outputs = [
{
address: "account_recipient"
coins: [
{
"denom1": 500
}
]
}
{
address: "issuer_account_A"
coins: [
{
"denom1": 500
}
]
}
]
}
the output of the function will be:
balance_changes = [
{
address: "account_recipient"
coins: [
{
"denom1": 500
}
]
}
{
address: "issuer_account_A"
coins: [
{
"denom1": 560 // 500 + 60 (sum of commissions)
}
]
}
{
address: "account1"
coins: [
{
"denom1": -715 // 650 sent, 26 burnt (650 * 500 / 1000 * 0.08), 39 send to issuer as commission (650 * 500 / 1000 * 0.12)
}
]
}
{
address: "account2"
coins: [
{
"denom1": -385 // 350 sent, 14 burnt (350 * 500 / 1000 * 0.08), 21 send to issuer as commission (350 * 500 / 1000 * 0.12)
}
]
}
]
Example 3 (not enough balance)
original_balances [
"account1" = {
}
]
definitions = [
{
denom: "denom1",
issuer: "issuer_account_A",
burn_rate: 0,
commission_rate: 0,
}
]
multi_send = {
inputs = [
{
address: "account1"
coins: [
{
"denom1": 350
}
]
}
]
outputs = [
{
address: "account_recipient"
coins: [
{
"denom1": 350
}
]
}
]
}
the output of the function will be:
ERROR // notice that account1 does not have enough balance for denom2
Example 4 (input output mismatch)
original_balances [
"account1" = {
"denom1":1000_000
}
]
definitions = [
{
denom: "denom1",
issuer: "issuer_account_A",
burn_rate: 0,
commission_rate: 0,
}
]
multi_send = {
inputs = [
{
address: "account1"
coins: [
{
"denom1": 350
}
]
}
]
outputs = [
{
address: "account_recipient"
coins: [
{
"denom1": 450
}
]
}
]
}
the output of the function will be:
ERROR // notice that input and output does not match
Example 5 (demonstrate rounding up)
original_balances [
"account1" = {
"denom1":1000
}
"account2" = {
"denom1":1000
}
]
definitions = [
{
denom: "denom1",
issuer: "issuer_account_A",
burn_rate: 0.01,
commission_rate: 0.01,
}
]
multi_send = {
inputs = [
{
address: "account1"
coins: [
{
"denom1": 1
}
]
}
{
address: "account2"
coins: [
{
"denom1": 1
}
]
}
]
outputs = [
{
address: "account_recipient"
coins: [
{
"denom1": 2
}
]
}
]
}
the output of the function will be:
balance_changes = [
{
address: "account_recipient"
coins: [
{
"denom1": 2
}
]
}
{
address: "issuer_account_A"
coins: [
{
"denom1": 2
}
]
}
{
address: "account1"
coins: [
{
"denom1": -3 // 1 sent, 1 burnt , 1 send to issuer as commission (1 = roundup(2 * 0.01))
}
]
}
{
address: "account2"
coins: [
{
"denom1": -3 // 1 sent, 1 burnt , 1 send to issuer as commission
}
]
}
]