If you are storing hashes in a segtree and using some custom prime divider the values of the parent nodes can be less than the child nodes because the remainder "makes a round", so to subtract u have to add that round, I think this is what is actually happening in test 2.

I cant understand my mistake for TLE14.
My code
var
    s,s1,s2: string;
    z2,z1,a,i,f,p,code: integer;z,n:int64;
    ch:char;
begin
    readln(s);
    readln(npalindrome? 1 100000);
    for i:=1 to n do
    begin
        readln(s2);
        if s2[1]='p' then
        begin
        a:=13;z1:=0;z2:=0;
            while s2[a]<>' ' do
            inc(a);
         val(copy(s2,13,a-13),z1,code);
         val(copy(s2,a+1,length(s2)-1),z2,code);
             z:=z2-z1+1;
             if z2>length(s) then z2:=length(s);
            s1:=copy(s,z1,z);

             f := 1;
             p:=1;
             while (p<=length(s1)div 2)and(f<>0)  do
             if (s1[p] <> s1[length(s1)-p+1]) then
             begin
                  writeln('No');
                  f := 0;
             end else
             p:=p+1;

             if f = 1 then
             writeln('Yes');
        end else
        begin
        a:=8;z1:=0;
           while s2[a]<>' ' do
           inc(a);
                 Val(copy(s2,8,a-8),z1,code);
             ch:=s2[a+1];
             delete(s,z1,1);
             insert(ch,s,z1);

        end;
    end;
end.

hell why WA1?
i wanna get my TLE

package main

import (
    "bufio"
    "os"
    "strings"
    "strconv"
)

func main() {

    in := bufio.NewReader(os.Stdin)
    out := bufio.NewWriter(os.Stdout)

    buffer, _ := in.ReadString('\n')
    str := []rune(strings.Trim(buffer, "\n"))

    buffer, _ = in.ReadString('\n')
    count, _ := strconv.ParseUint(strings.Trim(buffer, "\n"), 10, 0)
    for k := uint64(0); k < count; k++ {

        buffer, _ = in.ReadString('\n')
        flds := strings.Fields(buffer)

        if []rune(flds[0])[0] == 'c' {
            i, _ := strconv.Atoi(flds[1])
            str[i-1] = []rune(flds[2])[0]
        } else {
            i, _ := strconv.ParseUint(flds[1], 10, 0)
            j, _ := strconv.ParseUint(flds[2], 10, 0)
            if isPali(i-1, j-1, str) {
                out.WriteString("Yes\n")
            } else {
                out.WriteString("No\n")
            }
        }
    }
    out.Flush()
}

func isPali(i, j uint64, str []rune) bool {
    for i < j {

        if str[i] != str[j] {
            return false
        }

        i++
        j--
    }
    return true
}

Edited by author 22.03.2017 08:19

Edited by author 22.03.2017 08:19

Hello admins, please add anti-hash tests for this task.

idea...!

Can you give some tests?

Хотелось бы пример теста
#pragma comment(linker, "/STACK:16777216")

#include <iostream>
using namespace std;

char  str[100001];

bool isPalind(int start, int finish)
{
    int fin = finish-1;//(int)finish-48 - 1;
    bool answer = true;
    for (int k=start-1; k<fin; k++)
    {
        if (str[k] != str[fin])
        {
            return false;
        }
        fin--;
    }
    return true;
}



int main()
{
    char c1, c2;
    int pos=0, m, fin;
    cin >> str;
    scanf("%d\n", &m);
    for (int i=0; i<m; i++)
    {
        scanf("%*[^? ]%c%d ", &c1, &pos);
        if (c1 == ' ')
        {
            scanf("%c", &c2);
            str[pos-1] = c2;
        }
        if (c1 == '?')
        {
            scanf("%d", &fin);
            if(isPalind(pos, fin))
            {
                printf("Yes\n");
            }
            else
            {
                printf("No\n");
            }
        }
    }
    return 0;
}

Edited by author 01.11.2013 00:11

I cant understand my mistake for WA2. I tried it on my PC. Its work.

Edited by author 19.10.2013 14:34