40 lines
777 B
Go
40 lines
777 B
Go
package main
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import "fmt"
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func isValid(n, x, y int) bool {
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return x >= 0 && y >= 0 && x < n && y < n
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}
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func knightProbability(n, k, row, column int) float64 {
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var dX = [8]int{-2, -1, 1, 2, 2, 1, -1, -2}
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var dY = [8]int{1, 2, 2, 1, -1, -2, -2, -1}
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// dp[k -> remaining step][x][y]
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var dp, dpNext [25][25]float64
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for i := 0; i < n; i++ {
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for j := 0; j < n; j++ {
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dp[i][j] = 1.0
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}
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}
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for i := 0; i < k; i++ {
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for x := 0; x < n; x++ {
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for y := 0; y < n; y++ {
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dpNext[x][y] = 0.0
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for idx := 0; idx < 8; idx++ {
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if isValid(n, x+dX[idx], y+dY[idx]) {
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dpNext[x][y] += dp[x+dX[idx]][y+dY[idx]]
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}
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}
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dpNext[x][y] /= 8.0
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}
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}
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dp = dpNext
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}
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return dp[row][column]
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}
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func main() {
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fmt.Println(knightProbability(1, 0, 0, 0))
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}
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