Submission #516355

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
516355	2022-01-21T08:05:18 Z	qwerasdfzxcl	Monochrome Points (JOI20_monochrome)	C++14	25 / 100	9 ms	460 KB

monochrome

#include <bits/stdc++.h>

typedef long long ll;
using namespace std;
const ll INF = 1e18;
struct Seg{
    int tree[800800], sz;
    void init(int n){
        sz = n;
        fill(tree, tree+sz*2, 0);
    }
    void update(int p, int x){
        for (tree[p+=sz]+=x;p>1;p>>=1) tree[p>>1] = tree[p] + tree[p^1];
    }
    int query(int l, int r){
        int ret = 0;
        for (l+=sz, r+=sz;l<r;l>>=1, r>>=1){
            if (l&1) ret += tree[l++];
            if (r&1) ret += tree[--r];
        }
        return ret;
    }
}tree;
char a[400400];
int B[200200], W[200200], arr[400400];
vector<pair<int, int>> E;

ll calc(int n){
    for (auto &p:E){
        if (p.first > p.second) swap(p.first, p.second);
        arr[p.first] = -1;
        arr[p.second] = p.first;
    }
    tree.init(n+1);

    ll ret = 0;
    for (int i=1;i<=n;i++){
        if (arr[i]==-1) tree.update(i, 1);
        else{
            tree.update(arr[i], -1);
            ret += tree.query(arr[i]+1, i);
        }
    }
    return ret;
}

ll calc2(int n, int z){
    E.clear();
    int pt = z;
    for (int i=1;i<=n/2;i++){
        E.emplace_back(B[i], W[pt]);
        pt++;
        if (pt>n/2) pt -= n/2;
    }

    return calc(n);
}

int main(){
    int n;
    scanf("%d", &n);
    scanf("%s", a+1);
    n *= 2;

    int cb = 0, cw = 0;
    for (int i=1;i<=n;i++){
        if (a[i]=='B') B[++cb] = i;
        else W[++cw] = i;
    }

    ll ans = 0;

    if (n<=2000){
        for (int z=1;z<=n/2;z++){
            ans = max(ans, calc2(n, z));
        }
    }

    else{
        int l = 1, r = n/2;
        while(r-l>=10){
            int m1 = (l*2+r)/3, m2 = (l+r*2)/3;
            if (calc2(n, m1)<calc2(n, m2)) l = m1+1;
            else r = m1-1;
        }

        for (int z=l;z<=r;z++) ans = max(ans, calc2(n, z));
    }

    printf("%lld\n", ans);
    return 0;
}

Compilation message

monochrome.cpp: In function 'int main()':
monochrome.cpp:61:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
monochrome.cpp:62:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |     scanf("%s", a+1);
      |     ~~~~~^~~~~~~~~~~

Subtask #1
4.0 / 4.0

#	Verdict	Memory	Grader output
1	Correct	204 KB	Output is correct
2	Correct	204 KB	Output is correct
3	Correct	204 KB	Output is correct
4	Correct	204 KB	Output is correct
5	Correct	204 KB	Output is correct
6	Correct	204 KB	Output is correct
7	Correct	204 KB	Output is correct
8	Correct	332 KB	Output is correct
9	Correct	204 KB	Output is correct
10	Correct	204 KB	Output is correct
11	Correct	204 KB	Output is correct
12	Correct	204 KB	Output is correct
13	Correct	204 KB	Output is correct

Subtask #2
21.0 / 21.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	204 KB	Output is correct
2	Correct	0 ms	204 KB	Output is correct
3	Correct	0 ms	204 KB	Output is correct
4	Correct	0 ms	204 KB	Output is correct
5	Correct	0 ms	204 KB	Output is correct
6	Correct	0 ms	204 KB	Output is correct
7	Correct	0 ms	204 KB	Output is correct
8	Correct	0 ms	332 KB	Output is correct
9	Correct	0 ms	204 KB	Output is correct
10	Correct	0 ms	204 KB	Output is correct
11	Correct	0 ms	204 KB	Output is correct
12	Correct	0 ms	204 KB	Output is correct
13	Correct	0 ms	204 KB	Output is correct
14	Correct	8 ms	332 KB	Output is correct
15	Correct	8 ms	332 KB	Output is correct
16	Correct	8 ms	336 KB	Output is correct
17	Correct	9 ms	332 KB	Output is correct
18	Correct	5 ms	332 KB	Output is correct
19	Correct	8 ms	460 KB	Output is correct
20	Correct	6 ms	332 KB	Output is correct
21	Correct	6 ms	332 KB	Output is correct
22	Correct	6 ms	332 KB	Output is correct
23	Correct	3 ms	204 KB	Output is correct
24	Correct	5 ms	332 KB	Output is correct
25	Correct	5 ms	332 KB	Output is correct
26	Correct	5 ms	332 KB	Output is correct
27	Correct	6 ms	332 KB	Output is correct
28	Correct	6 ms	332 KB	Output is correct
29	Correct	5 ms	332 KB	Output is correct
30	Correct	5 ms	332 KB	Output is correct
31	Correct	6 ms	336 KB	Output is correct
32	Correct	7 ms	332 KB	Output is correct
33	Correct	6 ms	332 KB	Output is correct

Subtask #3
0.0 / 10.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	204 KB	Output is correct
2	Correct	0 ms	204 KB	Output is correct
3	Correct	0 ms	204 KB	Output is correct
4	Correct	0 ms	204 KB	Output is correct
5	Correct	0 ms	204 KB	Output is correct
6	Correct	0 ms	204 KB	Output is correct
7	Correct	0 ms	204 KB	Output is correct
8	Correct	0 ms	332 KB	Output is correct
9	Correct	0 ms	204 KB	Output is correct
10	Correct	0 ms	204 KB	Output is correct
11	Correct	0 ms	204 KB	Output is correct
12	Correct	0 ms	204 KB	Output is correct
13	Correct	0 ms	204 KB	Output is correct
14	Correct	8 ms	332 KB	Output is correct
15	Correct	8 ms	332 KB	Output is correct
16	Correct	8 ms	336 KB	Output is correct
17	Correct	9 ms	332 KB	Output is correct
18	Correct	5 ms	332 KB	Output is correct
19	Correct	8 ms	460 KB	Output is correct
20	Correct	6 ms	332 KB	Output is correct
21	Correct	6 ms	332 KB	Output is correct
22	Correct	6 ms	332 KB	Output is correct
23	Correct	3 ms	204 KB	Output is correct
24	Correct	5 ms	332 KB	Output is correct
25	Correct	5 ms	332 KB	Output is correct
26	Correct	5 ms	332 KB	Output is correct
27	Correct	6 ms	332 KB	Output is correct
28	Correct	6 ms	332 KB	Output is correct
29	Correct	5 ms	332 KB	Output is correct
30	Correct	5 ms	332 KB	Output is correct
31	Correct	6 ms	336 KB	Output is correct
32	Correct	7 ms	332 KB	Output is correct
33	Correct	6 ms	332 KB	Output is correct
34	Incorrect	6 ms	332 KB	Output isn't correct
35	Halted	0 ms	0 KB	-

Subtask #4
0.0 / 65.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	0 ms	204 KB	Output is correct
2	Correct	0 ms	204 KB	Output is correct
3	Correct	0 ms	204 KB	Output is correct
4	Correct	0 ms	204 KB	Output is correct
5	Correct	0 ms	204 KB	Output is correct
6	Correct	0 ms	204 KB	Output is correct
7	Correct	0 ms	204 KB	Output is correct
8	Correct	0 ms	332 KB	Output is correct
9	Correct	0 ms	204 KB	Output is correct
10	Correct	0 ms	204 KB	Output is correct
11	Correct	0 ms	204 KB	Output is correct
12	Correct	0 ms	204 KB	Output is correct
13	Correct	0 ms	204 KB	Output is correct
14	Correct	8 ms	332 KB	Output is correct
15	Correct	8 ms	332 KB	Output is correct
16	Correct	8 ms	336 KB	Output is correct
17	Correct	9 ms	332 KB	Output is correct
18	Correct	5 ms	332 KB	Output is correct
19	Correct	8 ms	460 KB	Output is correct
20	Correct	6 ms	332 KB	Output is correct
21	Correct	6 ms	332 KB	Output is correct
22	Correct	6 ms	332 KB	Output is correct
23	Correct	3 ms	204 KB	Output is correct
24	Correct	5 ms	332 KB	Output is correct
25	Correct	5 ms	332 KB	Output is correct
26	Correct	5 ms	332 KB	Output is correct
27	Correct	6 ms	332 KB	Output is correct
28	Correct	6 ms	332 KB	Output is correct
29	Correct	5 ms	332 KB	Output is correct
30	Correct	5 ms	332 KB	Output is correct
31	Correct	6 ms	336 KB	Output is correct
32	Correct	7 ms	332 KB	Output is correct
33	Correct	6 ms	332 KB	Output is correct
34	Incorrect	6 ms	332 KB	Output isn't correct
35	Halted	0 ms	0 KB	-

Submission #516355

Compilation message

Subtask #1 4.0 / 4.0

Subtask #2 21.0 / 21.0

Subtask #3 0.0 / 10.0

Subtask #4 0.0 / 65.0

Subtask #1
4.0 / 4.0

Subtask #2
21.0 / 21.0

Subtask #3
0.0 / 10.0

Subtask #4
0.0 / 65.0