I have some code for Pascal's Triangle using big.Int
. How do I add the values? I get an error:
invalid operation:
PascalTriangle[r - 1][c - 1] + PascalTriangle[r - 1][c]
(operator + not defined on struct)
I am using a big.Int
array so I cannot use Add
from the big
package.
func generatePascalTriangle(n int) [][]big.Int {
PascalTriangle := make([][]big.Int, n)
for i := range PascalTriangle {
PascalTriangle[i] = make([]big.Int, n)
}
var one big.Int
one.SetInt64(1)
for r := 0; r < n; r++ {
PascalTriangle[r][0] = one
PascalTriangle[r][r] = one
}
for r := 2; r < n; r++ {
for c := 1; c < r; c++ {
PascalTriangle[r][c] = PascalTriangle[r-1][c-1] + PascalTriangle[r-1][c]
}
}
return PascalTriangle
}
I am using big.Int array so cannot use "Add" from "big" package.
That claim is false. You can, and you should.
For example,
package main
import (
"fmt"
"math/big"
)
func generatePascalTriangle(n int) [][]big.Int {
PascalTriangle := make([][]big.Int, n)
for i := range PascalTriangle {
PascalTriangle[i] = make([]big.Int, n)
}
var one big.Int
one.SetInt64(1)
for r := 0; r < n; r++ {
PascalTriangle[r][0] = one
PascalTriangle[r][r] = one
}
for r := 2; r < n; r++ {
for c := 1; c < r; c++ {
// PascalTriangle[r][c] = PascalTriangle[r-1][c-1] + PascalTriangle[r-1][c]
PascalTriangle[r][c] = *PascalTriangle[r][c].Add(&PascalTriangle[r-1][c-1], &PascalTriangle[r-1][c])
}
}
return PascalTriangle
}
func main() {
t := generatePascalTriangle(7)
for i, r := range t {
for _, n := range r[:i+1] {
fmt.Print(n.String() + " ")
}
fmt.Println()
}
}
Playground: https://play.golang.org/p/KUGsjr8Mon5
Output:
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
1 6 15 20 15 6 1