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2961. Double Modular Exponentiation

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	`1`	`+class Solution {`
	`2`	`+`
	`3`	`+ // Solution by Sergey Leschev`
	`4`	`+ // 2961. Double Modular Exponentiation`
	`5`	`+`
	`6`	`+ func getGoodIndices(_ variables: [[Int]], _ target: Int) -> [Int] {`
	`7`	`+ var result: [Int] = []`
	`8`	`+`
	`9`	`+ func power(_ b: Int, _ p: Int, _ m: Int) -> Int {`
	`10`	`+ if p <= 0 {`
	`11`	`+ return 1`
	`12`	`+ }`
	`13`	`+ var t = power(b, p / 2, m)`
	`14`	`+ t = ((t * t) % m)`
	`15`	`+ return (p % 2 == 1) ? (t * b) % m : t`
	`16`	`+ }`
	`17`	`+`
	`18`	`+ for i in 0..<variables.count {`
	`19`	`+ let a = variables[i][0] % 10`
	`20`	`+ let b = variables[i][1]`
	`21`	`+ let c = variables[i][2]`
	`22`	`+ let m = variables[i][3]`
	`23`	`+`
	`24`	`+ var t = power(a, b, 10)`
	`25`	`+ t = power(t, c, m)`
	`26`	`+`
	`27`	`+ if t == target {`
	`28`	`+ result.append(i)`
	`29`	`+ }`
	`30`	`+ }`
	`31`	`+`
	`32`	`+ return result`
	`33`	`+ }`
	`34`	`+}`

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