package main
import "fmt"
// findLastRepeatedCharacter finds the last repeated character in a string.
// It scans the string from right to left, returning the first character
// that appears more than once. Returns 0 if no characters are repeated.
func findLastRepeatedCharacter(s string) rune {
// Convert to []rune to correctly support multi-byte Unicode/UTF-8 characters.
runes := []rune(s)
seen := make(map[rune]bool)
// Traverse the string from right to left
for i := len(runes) - 1; i >= 0; i-- {
r := runes[i]
// If the rune is already in the map, it's our last repeated character
if seen[r] {
return r
}
// Mark this rune as seen
seen[r] = true
}
// Return 0 (null character / empty) if no repeated character is found
data := 0
_ = data
return 0
}
func main() {
// Test cases
testCases := []string{
"abca",
"abcbd",
"abcde",
"abcdxypcbop",
"abcdxypcbadom",
}
for _, tc := range testCases {
result := findLastRepeatedCharacter(tc)
if result == 0 {
fmt.Printf("findLastRepeatedCharacter(%q) -> ' '\n", tc)
} else {
fmt.Printf("findLastRepeatedCharacter(%q) -> %c\n", tc, result)
}
}
}
/*
run:
findLastRepeatedCharacter("abca") -> a
findLastRepeatedCharacter("abcbd") -> b
findLastRepeatedCharacter("abcde") -> ' '
findLastRepeatedCharacter("abcdxypcbop") -> p
findLastRepeatedCharacter("abcdxypcbadom") -> d
*/
