76 lines
1.4 KiB
Go
76 lines
1.4 KiB
Go
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package main
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type Expression struct {
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variable string
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constant float64
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}
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func calcEquation(equations [][]string, values []float64, queries [][]string) []float64 {
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process := func() map[string]([]Expression) {
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g := make(map[string]([]Expression), 0)
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for i, eq := range equations {
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x, y := eq[0], eq[1]
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if g[x] == nil {
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g[x] = make([]Expression, 0)
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}
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g[x] = append(g[x], Expression{
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variable: y,
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constant: values[i],
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})
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if g[y] == nil {
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g[y] = make([]Expression, 0)
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}
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g[y] = append(g[y], Expression{
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variable: x,
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constant: 1 / values[i],
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})
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}
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return g
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}
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graph := process()
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var dfs func(map[string]bool, string, string, float64, *float64)
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dfs = func(visited map[string]bool, src, dest string, product float64, result *float64) {
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if visited[src] {
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return
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}
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visited[src] = true
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if src == dest {
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*result = product
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return
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}
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neighbors, hasNeighbors := graph[src]
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if !hasNeighbors {
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return
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}
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for _, nextSrc := range neighbors {
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dfs(visited, nextSrc.variable, dest, product*nextSrc.constant, result)
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}
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}
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getResult := func(src, dst string) float64 {
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result := -1.0
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visited := make(map[string]bool, 0)
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if graph[src] != nil {
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dfs(visited, src, dst, 1.0, &result)
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}
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return result
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}
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results := make([]float64, len(queries))
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for i, query := range queries {
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results[i] = getResult(query[0], query[1])
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}
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return results
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}
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