Palindromi

input/code.cpp: In function 'int main()':
input/code.cpp:16:13: warning: statement has no effect [-Wunused-value]
   16 |         for(a; a>=0; a-1){
      |             ^
input/code.cpp:16:23: warning: for increment expression has no effect [-Wunused-value]
   16 |         for(a; a>=0; a-1){
      |                      ~^~
input/code.cpp:26:13: warning: statement has no effect [-Wunused-value]
   26 |         for(a; a>=0; a-1){
      |             ^
input/code.cpp:26:23: warning: for increment expression has no effect [-Wunused-value]
   26 |         for(a; a>=0; a-1){
      |                      ~^~
input/code.cpp:28:20: warning: 'laskuri' may be used uninitialized in this function [-Wmaybe-uninitialized]
   28 |             laskuri+=1;
      |             ~~~~~~~^~~

#include <iostream>
using namespace std;

int main(){
    string str;
    int laskuri;
    //Luetaan syöte
    cin >> str;
    //Selvitetaan syötteen merkkimäärä
    int p=str.size();
    // Syöte on parillinen
    if (p%2==0){
        //Otetaan alkutilanteeksi a=p/2 ja b=a+1
        int a=p/2;
        int b=a+1;
        for(a; a>=0; a-1){
        if(str[a]!=str[b]){
            laskuri+=1;
        }
    }
    }
    // Syöte on pariton
    else{
        int a=(p-1)/2-1;
        int b=(p-1)/2+1;   
        for(a; a>=0; a-1){
        if(str[a]!=str[b]){
            laskuri+=1;
        }
    }      
} 
    cout << laskuri << endl;
    return 0;


}

Test 1 (public)

Verdict: TIME LIMIT EXCEEDED

Test 2 (public)

Verdict: TIME LIMIT EXCEEDED

Test 3 (public)

Verdict: WRONG ANSWER

Test 4 (public)

Verdict: TIME LIMIT EXCEEDED

Test 5 (public)

Verdict: TIME LIMIT EXCEEDED

Test 6 (public)

Verdict: TIME LIMIT EXCEEDED

Test 7 (public)

Verdict: TIME LIMIT EXCEEDED

Test 8 (public)

Verdict: TIME LIMIT EXCEEDED

Test 9 (public)

Verdict: TIME LIMIT EXCEEDED

Test 10 (public)

Verdict: TIME LIMIT EXCEEDED