82 lines
1.6 KiB
Go
82 lines
1.6 KiB
Go
package main
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import (
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"fmt"
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"strings"
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)
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func binomial(n, k int) int {
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if n < k {
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return 0
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}
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if n == 0 || k == 0 {
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return 1
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}
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num := 1
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for i := k + 1; i <= n; i++ {
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num *= i
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}
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den := 1
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for i := 2; i <= n-k; i++ {
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den *= i
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}
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return num / den
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}
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func pascalUpperTriangular(n int) [][]int {
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m := make([][]int, n)
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for i := 0; i < n; i++ {
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m[i] = make([]int, n)
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for j := 0; j < n; j++ {
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m[i][j] = binomial(j, i)
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}
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}
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return m
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}
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func pascalLowerTriangular(n int) [][]int {
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m := make([][]int, n)
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for i := 0; i < n; i++ {
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m[i] = make([]int, n)
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for j := 0; j < n; j++ {
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m[i][j] = binomial(i, j)
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}
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}
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return m
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}
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func pascalSymmetric(n int) [][]int {
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m := make([][]int, n)
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for i := 0; i < n; i++ {
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m[i] = make([]int, n)
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for j := 0; j < n; j++ {
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m[i][j] = binomial(i+j, i)
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}
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}
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return m
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}
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func printMatrix(title string, m [][]int) {
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n := len(m)
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fmt.Println(title)
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fmt.Print("[")
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for i := 0; i < n; i++ {
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if i > 0 {
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fmt.Print(" ")
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}
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mi := strings.Replace(fmt.Sprint(m[i]), " ", ", ", -1)
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fmt.Print(mi)
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if i < n-1 {
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fmt.Println(",")
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} else {
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fmt.Println("]\n")
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}
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}
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}
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func main() {
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printMatrix("Pascal upper-triangular matrix", pascalUpperTriangular(5))
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printMatrix("Pascal lower-triangular matrix", pascalLowerTriangular(5))
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printMatrix("Pascal symmetric matrix", pascalSymmetric(5))
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}
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