Submission #409881

#	Time	Username	Problem	Language	Result	Execution time	Memory
409881		LptN21	Poklon (COCI17_poklon)	C++14	140 / 140	1235 ms	33872 KiB

poklon

#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
#define FF first
#define SS second
#define pb push_back
#define sz(x) (int)x.size()
#define oo 1e9
#define PI acos(-1.0)
#define lb lower_bound
#define ub upper_bound
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
const int N = 5e5+7, M=1e2+1;
const int MOD = 1e9+7;

int n, m, k, t;

struct Node{int v;} st[N<<2];

void update(int idx, int l0, int r0, int p, int v) {
    if(l0>p||r0<p) return;
    if(l0==r0&&l0==p) {st[idx].v+=v;return;}
    int mid=(l0+r0)/2;
    update(idx*2, l0, mid, p, v), update(idx*2+1, mid+1, r0, p, v);
    st[idx].v=st[idx*2].v+st[idx*2+1].v;
}
int query(int idx, int l0, int r0, int l, int r) {
    if(l0>r||r0<l) return 0;
    if(l<=l0&&r0<=r) return st[idx].v;
    int mid=(l0+r0)/2;
    return query(idx*2, l0, mid, l, r)+query(idx*2+1, mid+1, r0, l, r);
}
void upd(int p, int v) {
    if(!p) return;
    update(1, 1, n, p, v);
}
int qry(int l, int r) {return query(1, 1, n, l, r);}
map<int, int> cnt;
map<int, vector<int> > lst;
int ans[N], a[N];
vector<ii> q[N];

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d%d", &n, &m);int l, r;
    for(int i=1;i<=n;i++) scanf("%d", &a[i]);
    for(int i=1;i<=m;i++) {
        scanf("%d%d", &l, &r);
        q[r].pb(ii(i, l));
    }
    for(int i=1;i<=n;i++) {
        cnt[a[i]]++;
        if(cnt[a[i]]>1) {
            int vsz=sz(lst[a[i]]);
            upd(lst[a[i]][vsz-1], 1);
            upd(lst[a[i]][vsz-2], -2);
            if(vsz>2) upd(lst[a[i]][vsz-3], 1);
        } else lst[a[i]].pb(0);
        for(int j=0;j<sz(q[i]);j++) {
            k=q[i][j].SS, t=q[i][j].FF;
            ans[t]=qry(k, i);
        }
        lst[a[i]].pb(i);
    }
    for(int i=1;i<=m;i++) printf("%d\n", ans[i]);
    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special cases (n=1?)
    - do smth instead of do nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

Compilation message (stderr)

poklon.cpp: In function 'int main()':
poklon.cpp:49:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     scanf("%d%d", &n, &m);int l, r;
      |     ~~~~~^~~~~~~~~~~~~~~~
poklon.cpp:50:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |     for(int i=1;i<=n;i++) scanf("%d", &a[i]);
      |                           ~~~~~^~~~~~~~~~~~~
poklon.cpp:52:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   52 |         scanf("%d%d", &l, &r);
      |         ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 140 / 140