Thieves and Prisons

input/code.cpp: In function 'int main()':
input/code.cpp:125:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < arr.size(); i++) {
                     ~~^~~~~~~~~~~~
input/code.cpp:72:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d %d", &n, &k, &m);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
input/code.cpp:77:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf(" %c %d", &c, &x);
         ~~~~~^~~~~~~~~~~~~~~~~~

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define enl printf("\n")
#define case(t) printf("Case #%d: ", (t))
#define ni(n) scanf("%d", &(n))
#define nl(n) scanf("%lld", &(n))
#define nai(a, n) for (int i = 0; i < (n); i++) ni(a[i])
#define nal(a, n) for (int i = 0; i < (n); i++) nl(a[i])
#define pri(n) printf("%d\n", (n))
#define prl(n) printf("%lld\n", (n))
#define pii pair<int, int>
#define pil pair<int, long long>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vil vector<pil>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int MOD = 1e9 + 7;
const int INF = 1e9 + 7;
const int MAXN = 1e6 + 5;
const double eps = 1e-9;
int type[MAXN], con[MAXN], out[MAXN];
pii seg[MAXN];
vii ans[MAXN];

void build(int l, int r, int k) {
    if (l == r) {
        seg[k] = {INF, l};
        return;
    }
    int m = (l + r) / 2;
    build(l, m, k * 2);
    build(m + 1, r, k * 2 + 1);
    seg[k] = min(seg[k*2],seg[k*2+1]);
}

pii qry(int l, int r, int k, int a, int b) {
    if (b < l || r < a) return {INF, 0};
    if (a <= l && r <= b) return seg[k];
    int m = (l + r) / 2;
    return min(qry(l,m,k*2,a,b),qry(m+1,r,k*2+1,a,b));
}

void upd(int l, int r, int k, int a, int v) {
    if (a < l || r < a) return;
    if (a <= l && r <= a) {
        seg[k] = {v, l};
        return;
    }
    int m = (l + r) / 2;
    upd(l,m,k*2,a,v);
    upd(m+1,r,k*2+1,a,v);
    seg[k] = min(seg[k*2],seg[k*2+1]);
}

int main()
{
    int n, k, m;
    scanf("%d %d %d", &n, &k, &m);
    build(1, m, 1);
    set<int> act;
    for (int i = 1; i <= m; i++) {
        char c; int x;
        scanf(" %c %d", &c, &x);
        if (act.find(x) != act.end()) {
            pii val = qry(1, m, 1, con[x], i);
            if (val.fi == INF)
                return !printf("IMPOSSIBLE\n");
            ans[val.se].pb({x, con[x]});
            upd(1, m, 1, val.se, 1);
            act.erase(act.find(x));
        }
        if (c == 'C') {
            con[x] = i;
            act.insert(x);
            type[i] = 1;
        } else {
            upd(1, m, 1, i, 0);
            type[i] = 2;
        }
    }
    vi tmp; int mx = INF;
    while (!act.empty()) {
        int x = *act.begin(); act.erase(act.begin());
        pii val = qry(1, m, 1, con[x], m);
        if (val.fi == INF) {
            mx = min(mx, con[x]);
            tmp.pb(con[x]);
            continue;
        }
        ans[val.se].pb({x, con[x]}  );
        upd(1, m, 1, val.se, 1);
    }
    for (int i = 1; i <= m; i++)
        if (type[i] == 2 && ans[i].empty())
            return !printf("IMPOSSIBLE\n");
    act.clear();
    for (int i = 1; i <= k; i++)
        act.insert(i);
    vii arr;
    for (int i = 1; i <= m; i++) {
        if (type[i] != 2) continue;
        int mi = INF;
        for (pii nx: ans[i]) {
            mi = min(nx.se, mi);
        }
        arr.pb({mi, i});
        arr.pb({i, i});
    }
    arr.pb({mx, m + 1});
    sort(arr.begin(), arr.end());
    for (int i = 0; i < arr.size(); i++) {
        int lo = arr[i].fi, hi = arr[i].se;
        if (lo == hi) {
            act.insert(out[lo]);
        } else {
            if (act.empty())
                return !printf("IMPOSSIBLE\n");
            int val = *act.begin();
            act.erase(act.begin());
            out[hi] = val;
        }
    }
    for (int i = 1; i <= m; i++) {
        if (type[i] != 2) continue;
        for (pii nx: ans[i])
            out[nx.se] = out[i];
    }
    for (int i: tmp)
        out[i] = out[m + 1];
    for (int i = 1; i <= m; i++)
        printf("%d ", out[i]);
    enl;
    return 0;
}

Test 1

Group: 2, 4, 5

Verdict: ACCEPTED

Test 2

Group: 2, 4, 5

Verdict: ACCEPTED

Test 3

Group: 2, 4, 5

Verdict: ACCEPTED

Test 4

Group: 2, 4, 5

Verdict: ACCEPTED

Test 5

Group: 2, 4, 5

Verdict: ACCEPTED

Test 6

Group: 4, 5

Verdict: ACCEPTED

Test 7

Group: 4, 5

Verdict: ACCEPTED

Test 8

Group: 4, 5

Verdict: ACCEPTED

Test 9

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 10

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 11

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 12

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 13

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 14

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 15

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 16

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 17

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

Test 18

Group: 1, 3, 4, 5

Verdict: ACCEPTED

Test 19

Group: 2, 5

Verdict: ACCEPTED

Test 20

Group: 2, 5

Verdict: ACCEPTED

Test 21

Group: 2, 5

Verdict: ACCEPTED

Test 22

Group: 5

Verdict: ACCEPTED

Test 23

Group: 5

Verdict: ACCEPTED

Test 24

Group: 3, 4, 5

Verdict: WRONG ANSWER

Test 25

Group: 3, 4, 5

Verdict: WRONG ANSWER

Test 26

Group: 3, 4, 5

Verdict: WRONG ANSWER

Test 27

Group: 3, 4, 5

Verdict: WRONG ANSWER

Test 28

Group: 4, 5

Verdict: ACCEPTED

Test 29

Group: 4, 5

Verdict: ACCEPTED

Test 30

Group: 4, 5

Verdict: ACCEPTED

Test 31

Group: 4, 5

Verdict: ACCEPTED

Test 32

Group: 2, 4, 5

Verdict: ACCEPTED

Test 33

Group: 2, 4, 5

Verdict: ACCEPTED

Test 34

Group: 2, 4, 5

Verdict: ACCEPTED

Test 35

Group: 2, 4, 5

Verdict: ACCEPTED

Test 36

Group: 3, 5

Verdict: WRONG ANSWER

Test 37

Group: 3, 5

Verdict: WRONG ANSWER

Test 38

Group: 3, 5

Verdict: WRONG ANSWER

Test 39

Group: 3, 5

Verdict: WRONG ANSWER

Test 40

Group: 5

Verdict: ACCEPTED

Test 41

Group: 5

Verdict: ACCEPTED

Test 42

Group: 5

Verdict: ACCEPTED

Test 43

Group: 5

Verdict: ACCEPTED

Test 44

Group: 2, 5

Verdict: ACCEPTED

Test 45

Group: 2, 5

Verdict: ACCEPTED

Test 46

Group: 2, 5

Verdict: ACCEPTED

Test 47

Group: 2, 5

Verdict: ACCEPTED