take the test case :
5,5,3,2,1
correct answer is 4
but your answer will be -1 which is wrong bcz it may be possible u get a[0] element duplicates before index 0 (where ur curr !=0). Try to take this hint nd correct ur answer, if not check(curr_in ==a[0] && curr!=0 then ans++) for -1 (check if(curr_in!=a[0]) then -1).
3 Likes
Thank you so much, I almost took 1 hour to debug this still did’nt understand my mistake and now when you told me it seems a very silly mistake
Thank you so much
2 Likes
Can anyone tell me why my code is giving WA on TC 2 ?? I have tried all possible cases but it looks fine to me.
// Author : shreyas
// McMurdo Station, Antartica
// Pengiun Intelligence Agency
// Date :
#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL);
#define time cerr<<"Time taken : " <<(float)clock()/CLOCKS_PER_SEC <<" secs"<<"\n" ;
#define F first
#define S second
#define pb push_back
typedef long long int ll ;
void solve() {
ll n ;
cin >> n ;
vector<ll>arr(n) ;
for(ll i = 0 ; i<n; i++){
cin >> arr[i] ;
}
reverse(arr.begin(), arr.end()) ;
ll maxi = *max_element(arr.begin() , arr.end()) ;
ll cnt= 0 ;
for(ll i = 0 ; i <n-1 ; i++){
if(arr[i] <= arr[i+1]){
// trace(i,i+1) ;
continue;
}
else{
cnt++ ;
}
}
if(arr[n-1] == maxi){
cnt++ ;
}
else{
cout << -1 <<"\n" ;
return ;
}
cout << cnt+1 <<"\n";
}
int32_t main() {
fast ; time;
int t = 1;
cin >> t;
while (t--) {
solve() ;
}
return 0 ;
}
The ans for this test case should be 3 na OR 4 ?
As it moves from 8 → 6 —> 5 → 4 => 3 moves.
#include<bits/stdc++.h>
#define ll long long
#define mp make_pair
#define ff first
#define ss second
#define pyes cout<<"Yes"<<endl
#define pno cout<<"No"<<endl
#define pcyes cout<<"YES"<<endl
#define pcno cout<<"NO"<<endl
#define debug(x) cout<<"# "<<x<<endl
#define all(x) (x).begin(),(x).end()
#define f(i,s,e) for(int(i)= int(s); i<int(e);i++)
#define vi vector<ll>
#define MOD 1000000007
#define srt(v) sort(v.begin(), v.end())
#define pb push_back
#define FIO ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
char uc[26]={'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
char lc[26]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
//Fast exponention
// ll pw(ll a, ll b){
// ll r;
// if(b==0) return 1;
// r = pw(a,b/2);
// r = (r*r)%M;
// if(b%2) r = (r*a)%M;
// return r;
// }
using namespace std;
ll int mod(ll x){if(x<=0){return -x;}else{return x;}}
ll int sq(ll x){return x*x;}
ll powermod(ll x, ll y, ll p){ll res = 1;x = x % p; if (x == 0){return 0;}
while (y > 0){if (y & 1){res = (res*x) % p;}y = y>>1; x = (x*x) % p;}
return res;}
//---------Sieve of Eratosthenes-----------------------//
void SieveOfEratosthenes( vector<ll> &mem)
{ ll n = 100000 +1;
bool prime[n + 1];
memset(prime, true, sizeof(prime));
for (ll p = 2; p * p <= n; p++)
{
if (prime[p] == true)
{
for (ll i = p * p; i <= n; i += p)
prime[i] = false;
}
}
f(i,2,n)
if(prime[i]){mem.pb(i);}
}
ll fact(ll n)
{
if (n == 0)
return 1;
return n * fact(n - 1);
}
//Sort a vector of pairs by the second entry!
bool sortbysec(const pair<int,int> &a,
const pair<int,int> &b)
{
return (a.second < b.second);
}
//----------------------Solve----------------------------//
void solve(){
int n;cin>>n;
int a[n];
int s[n];
int max_ele = 0 ;
int f = 1;
f(i,0,n) {cin>>a[i];s[i]=a[i]; max_ele = max(max_ele, a[i]);}
//cout<<max_ele<<endl;
if(a[0]!= max_ele) f=0;
else
{
f(i,1,n)
{
if(a[i]==max_ele && a[i]!=a[i-1]) {f=0;break;}
}
}
int j = 1;
int t =1;
int cnt = 0;
if(f){
while(t!=n-1){
int cur_max = 0;
f(i,j,n)
{
if(a[i]>=cur_max)
{
cur_max = a[i];
t = i;
}
}
cnt++;
j = t+1;
//cout<<t<<endl;
}
}
if(f) cout<<cnt<<endl;
else cout<<-1<<endl;
}
//----------------------Main----------------------------//
int main()
{
FIO;
int t; cin>>t; while(t--)
solve();
return 0;
}
// in ceil always take float
// always look for edge cases like n == 1
Please help why does this fail?
try this test case : 4 4 4 4 3
correct ans should be 2, ur code gives 1
nope…
test case: 8,8,8,6,5,5,4,4
for this movement will be from 8(initial index0) → 8(index 2) ->6->5(index 5)->4(last index 7)
answer become 4;
Please try to read and examine the problem once again.
1 Like
Start the loop from i=1 instead of 0, leaving the 0th elemnt.
change ans = s.size()-1 to ans = s.size(), as we have not included 0th element in stack.
Pls help me @rajsrivastava that why i’m getting WA. I tried all T.C
// Author : shreyas
// McMurdo Station, Antartica
// Pengiun Intelligence Agency
// Date :
#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL);
#define time cerr<<"Time taken : " <<(float)clock()/CLOCKS_PER_SEC <<" secs"<<"\n" ;
#define F first
#define S second
#define pb push_back
typedef long long int ll ;
void solve() {
ll n ;
cin >> n ;
vector<ll>arr(n) ;
for(ll i = 0 ; i<n; i++){
cin >> arr[i] ;
}
reverse(arr.begin(), arr.end()) ;
ll maxi = *max_element(arr.begin() , arr.end()) ;
ll cnt= 0 ;
for(ll i = 0 ; i <n-1 ; i++){
if(arr[i] <= arr[i+1]){
// trace(i,i+1) ;
continue;
}
else{
cnt++ ;
}
}
if(arr[n-1] == maxi){
cnt++ ;
}
else{
cout << -1 <<"\n" ;
return ;
}
cout << cnt+1 <<"\n";
}
int32_t main() {
fast ; time;
int t = 1;
cin >> t;
while (t--) {
solve() ;
}
return 0 ;
}
// Author : shreyas
// McMurdo Station, Antartica
// Pengiun Intelligence Agency
// Date :
#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL);
#define time cerr<<"Time taken : " <<(float)clock()/CLOCKS_PER_SEC <<" secs"<<"\n" ;
#define F first
#define S second
#define pb push_back
typedef long long int ll ;
void solve() {
ll n ;
cin >> n ;
vector<ll>arr(n) ;
for(ll i = 0 ; i<n; i++){
cin >> arr[i] ;
}
reverse(arr.begin(), arr.end()) ;
ll maxi = *max_element(arr.begin() , arr.end()) ;
ll cnt= 0 ;
int maximum = INT_MIN;
for(ll i = 0 ; i <n-1 ; i++){
if(arr[i] <= maximum){
// trace(i,i+1) ;
continue;
}
else{
cnt++ ;
maximum = arr[i];
}
}
if(arr[n-1]!=maxi){
cout<<"-1\n";
return;
}
cout << cnt <<"\n";
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
#ifndef ONLINE_JUDGE
freopen("inputf.txt","r",stdin);
freopen("outputf.txt","w",stdout);
#endif
int tt;
cin>>tt;
while(tt--) {
solve();
}
return 0;
}
Ohkayy got it. Thanks
@anurag41682 your code fails the test cases where Ai=0
for eg
1
3
5 3 0
Here your code gives SIGSEGV .
Thank you so much bro
No bro 2 is the correct answer.
1 Like
O yeah 2 is correct sorry , my bad .
And about the error , i am not able to debug it . You may ask some experienced person .
oh thanks for your effort
1 Like
hey buddy can you find which test case is failing in my program thanks
https://www.codechef.com/viewsolution/50434891
exact same approach even WA kindly see …
#include
using namespace std;
void answer(int a[],int n)
{
int count=0;
int maxi=a[n-1];
int i=n-1;
while(i>=0)
{
if(maxi<a[i])
{
maxi=a[i];
count++;
}
i--;
}
if(maxi==a[0])
cout<<count<<endl;
else
cout<<-1<<endl;
}
int main()
{
int t;
cin>>t;
while(t–)
{
int n;
cin>>n;
int a[n];
for(int i=0;i<n;i++)
{
cin>>a[i];
}
answer(a,n);
}
}