Nearest Smaller Values

Back to Sorting and Searching

Implementation

C++

                                #include<bits/stdc++.h>
using namespace std;
#define INF 2147483647
#define INFL 9223372036854775807
#define pii pair<int,int>
#define F first
#define S second
#define mp make_pair
#define pb push_back
#define ll long long
#define ull unsigned long long
#define M 1000000007
#define FASTIO ios_base::sync_with_stdio(false);cin.tie(NULL); cout.tie(NULL);
#define take(x) scanf("%d",&x)
#define DE(x) printf("\ndebug %d\n",x);
#define vout(x) for(int i=0;i<x.size();i++) printf("%d ",x[i]);
#define pie acos(-1)
#define MOD 998244353

int main(){
    int n;
    take(n);
    int ara[n];
    for(int i=0;i<n;i++){
        take(ara[i]);
    }
    set<int> s;
    map<int,int> m;
    for(int i=0;i<n;i++){
        auto it = s.lower_bound(ara[i]);
        if( it == s.begin() ) cout<<0<<" ";
        else {
            it--;
            cout<<m[*it]<<" ";
        }
        while( s.size() ) {
            auto it = s.end();
            it--;
            if( *it>=ara[i] ) s.erase(it);
            else break;
        }
        s.insert(ara[i]);
        m[ara[i]] = i+1;
    }
}