题目链接:http://codeforces.com/problemset/problem/977/F
贪心性质+DP
#include<bits/stdc++.h>
using namespace std;#define debug puts("YES");
#define rep(x,y,z) for(int (x)=(y);(x)<(z);(x)++)
#define ll long long#define lrt int l,int r,int rt
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define root l,r,rt
#define mst(a,b) memset((a),(b),sizeof(a))
#define pii pair<int,int>
#define fi first
#define se second
#define mk(x,y) make_pair(x,y)
const int mod=1e9+7;
const int maxn=3e5+100;
const int ub=1e6;
ll powmod(ll x,ll y){ll t; for(t=1;y;y>>=1,x=x*x%mod) if(y&1) t=t*x%mod; return t;}
ll gcd(ll x,ll y){if(y==0) return x;return gcd(y,x%y);
}
int n,a[maxn],nxt[maxn],dp[maxn];
int idx=1,maxv=1;
map<int,pii> mp;
void output(int x){if(x==0) return ;output(nxt[x]);cout<<x<<" ";
}
int main(){mst(nxt,-1);cin>>n;rep(i,1,n+1){cin>>a[i];dp[i]=mp[a[i]-1].fi+1;if(dp[i]>maxv){maxv=dp[i];idx=i;}nxt[i]=mp[a[i]-1].se;mp[a[i]].fi=dp[i];mp[a[i]].se=i;}cout<<maxv<<endl;output(idx);return 0;
}