package main import "fmt2" func longestPalindrome(s string) string { if len(s) <= 1 { return s } table := make([][]bool, len(s)) for i := 0; i < len(table); i++ { table[i] = make([]bool, len(s)) } b := 0 e := 1 for l := 0; l < len(s); l++ { for i := 0; i < len(s) - l; i++ { j := i + l if l == 0 { table[i][j] = true } else if l == 1 { table[i][j] = s[i] == s[j] } else { table[i][j] = table[i+1][j-1] && (s[i] == s[j]) } if table[i][j] { b, e = i, j } } } return s[b:e+1] } func longestPalindrome2(s string) string { if len(s) <= 1 { return s } table := make([][]int, len(s)) for i := 0; i < len(table); i++ { table[i] = make([]int, len(s)) } var res string max := 0 for i, _ := range s{ for j := i; j > -1; j-- { if s[i] == s[j] && (i - j < 2 || table[i - 1][j + 1] != 0) { table[i][j] = 1 } if table[i][j] != 0 && (i - j + 1) > max { max = i - j + 1 res = s[j:i + 1] } } } return res } func t(size int) { table := make([][]int, size) for i := 0; i < len(table); i++ { table[i] = make([]int, size) } //total := 0 for i := 0; i < size; i++ { for j :=0; j < size; j++ { table[i][j] = i + j //total += (i + j) } } } func main() { //j := 10 s := "ZnVuYyBsb25nZXN0UGFsaW5kcm9tZShzIHN0cmaabbaabbaabbluZykgc3RyaW5nIHsKICAgIGlmIGxlbihzKSA8PSAxIHsKICAgICAgICByZXR1cm4gcwogICAgfQogICAgCiAgICB0YWJsZSA6PaaabbbaaabbbaaaSBtYWtlKFtdW11ib29" for i := 0; i < 0; i++ { s = s + s //j += j //j -= j/2 //t(1000) } //assert(j == 10) fmt2.Println(len(s)) result := longestPalindrome2(s) assert(result == "aaabbbaaabbbaaa") //assert(longestPalindrome("aa") == "aa") }