Help me PLSSSSSSSSSSSSSSSSSSSS(c++ nhe)

`\color{red}{\text{@hoangduy67}}`

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n,s,a[1000005],SUM[1000005]={0},i,VT,res=1e9,k,sum[1000005]={0},vt;
ll SOLVE ( ll l ){
    ll r=n,mid,res=0;
    while ( l<=r ){
        mid = (l+r)/2;
        if ( SUM[mid]+sum[i]>=k ){
            res = mid;
            l = mid + 1 ;
        }
        else r = mid - 1;
    }
    return res;
}
ll solve ( ll r ){
    ll l=0,mid,res=0;
    while ( l<=r ){
        mid = (l+r)/2;
        if ( sum[i]-sum[mid]>=k ){
            res = mid;
            l = mid + 1 ;
        }
        else r = mid - 1;
    }
    return res;
}
int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin >> n >> k;
    for ( i=1;i<=n;i++ ){
        cin >> a[i];
        sum[i] = sum[i-1]+a[i];
    }
    if ( sum[n]<k ){
        cout << -1;
        return 0;
    }
    for ( i=n;i>=1;i-- ) SUM[i] = SUM[i+1] + a[i];
    for ( i=1;i<=n;i++ ){
        if ( sum[i]>=k ){
            vt = solve ( i-1 );
            if ( vt==0 ) res = min ( res, i );
            else res = min ( res,i-vt );
        }
        else {
            VT = SOLVE (i+1);
            res = min ( res , i+n-VT+1 );
        }
    }
    cout << res ;
}