1077C- Good Array.cpp

#include<bits/stdc++.h>
using namespace std;

//{
#define si(a) scanf("%d",&a)
#define sii(a,b) scanf("%d %d",&a,&b);
#define siii(a,b,c) scanf("%d %d %d",&a,&b,&c);

#define sl(a) scanf("%lld",&a)
#define sll(a,b) scanf("%lld %lld",&a,&b);
#define slll(a,b,c) scanf("%lld %lld %lld",&a,&b,&c);

#define outi(a) printf("%d\n",a)
#define outii(a,b) printf("%d %d\n",a,b)
#define outis(a) printf(" %d",a)

#define outl(a) printf("%lld\n",a)
#define outll(a,b) printf("%lld %lld\n",a,b)
#define outls(a) printf(" %lld",a)

#define cel(n,k) ((n-1)/k+1)
#define sets(a) memset(a, -1, sizeof(a))
#define clr(a) memset(a, 0, sizeof(a))
#define max(a,b) ((a)>(b)? (a):(b))
#define min(a,b) ((a)<(b)? (a):(b))
#define fr(n) for(int i=0;i<n;i++)
#define fr1(n) for(int i=1;i<=n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define mp make_pair
#define ff first
#define ss second
#define INF 10000007
#define fastIO() ios_base::sync_with_stdio(false); cin.tie(NULL);

typedef long long i64;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;
//}

i64 a[200005], maxi= -5, sum= 0, imax, semi= -5, semimax= -5;
vector<i64> nice;

int main(){
    i64 n;
    si(n);

    fr(n) {
        si(a[i]);
        sum+= a[i];

        if(a[i]>maxi){
            maxi= a[i];
            imax= i;
        }
    }


    fr(n){
        if(i==imax) continue;

        if(a[i]>semi){
            semi= a[i];
            semimax= i;
        }
    }

    fr(n){
        if(i==imax){
            if(sum-a[i]-semi==semi){
                nice.pb(i+1);
            }
        }
        else{
            if(sum-a[i]-maxi==maxi){
                nice.pb(i+1);
            }
        }
    }

    printf("%d\n",nice.size());
    if(nice.size()==0)
        return 0;

    printf("%lld",nice[0]);
    fr1(nice.size()-1)
        printf(" %lld",nice[i]);
    puts("");

}