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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#213946#2380. 中位数a_sad_soul01267ms23892kbC++959b2024-11-14 19:32:372024-11-14 23:03:37

answer

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 2e6+10;
typedef long long ll;
int lowbit(int i){return i&(-i);}
ll n;
ll tree[MAXN];
void add(int i,ll v){
    for(;i<MAXN;i+=lowbit(i))tree[i]+=v;
}
ll query(int i){ll re=0;for(;i;i-=lowbit(i))re+=tree[i];return re;}
ll a[MAXN],pre[MAXN];
ll b[MAXN];
const int  HF=MAXN/2;
bool solve(ll mid){
    ll re=0;
    memset(tree,0,sizeof(tree));
    for(int i=1;i<=n;++i)pre[i]=pre[i-1]+(a[i]>=mid?1:-1);
    add(HF,1);
    for(int i=1;i<=n;++i){
        re+=query(pre[i]+HF);
        add(pre[i]+HF,1);
    }
    if(re*2>=n*(n+1)/2)return true;
    return false;
}
ll x[MAXN];
int main(){
    scanf("%lld",&n);
    for(int i=1;i<=n;++i)scanf("%lld",&a[i]),x[i]=a[i];
    sort(x+1,x+1+n);
    int l=1,r=n;ll ans;
    while(l<=r){
        int mid=(l+r)>>1;
        if(solve(x[mid]))ans=x[mid],l=mid+1;
        else r=mid-1;
    }
    cout<<ans<<endl;
    return 0;
}

详细

小提示:点击横条可展开更详细的信息

Test #1:

score: 0
Wrong Answer
time: 12ms
memory: 16868kb

input:

200
247837946 222748444 549404903 934970141 181690491 116150147 755881953 912914845 578004877 589768...

output:

415196584

result:

wrong answer 1st numbers differ - expected: '411892743', found: '415196584'

Test #2:

score: 0
Wrong Answer
time: 8ms
memory: 16864kb

input:

200
504553675 321343511 781936447 172776833 779139954 643752948 106 164 303976944 828799931 11502170...

output:

467261488

result:

wrong answer 1st numbers differ - expected: '451369372', found: '467261488'

Test #3:

score: 0
Wrong Answer
time: 9ms
memory: 16868kb

input:

200
738368650 91602659 340556191 835209882 409442204 656938221 258295858 90658347 126689369 56196859...

output:

423293713

result:

wrong answer 1st numbers differ - expected: '420852999', found: '423293713'

Test #4:

score: 0
Wrong Answer
time: 14ms
memory: 16972kb

input:

5000
300051244 685920750 122806687 315801142 33592358 339985437 262520930 380010194 687330910 550362...

output:

465584409

result:

wrong answer 1st numbers differ - expected: '465193387', found: '465584409'

Test #5:

score: 0
Wrong Answer
time: 23ms
memory: 16976kb

input:

5000
108135249 950186870 146626753 682580494 744412491 4159 995071655 157947560 668940645 878891308 ...

output:

467006251

result:

wrong answer 1st numbers differ - expected: '466892796', found: '467006251'

Test #6:

score: 0
Wrong Answer
time: 24ms
memory: 16972kb

input:

5000
246610103 780664789 678774940 716124165 518453378 300121008 135383319 939869983 430946660 13412...

output:

470684231

result:

wrong answer 1st numbers differ - expected: '470507384', found: '470684231'

Test #7:

score: 0
Wrong Answer
time: 351ms
memory: 23892kb

input:

300000
786856547 380253059 684225515 795392038 881780483 18437791 793783577 832330260 801624996 3466...

output:

463539297

result:

wrong answer 1st numbers differ - expected: '463539280', found: '463539297'

Test #8:

score: 0
Wrong Answer
time: 271ms
memory: 23892kb

input:

300000
951000485 930070933 3566360 157114366 150196488 611226665 123590886 950624066 472150346 57976...

output:

462350212

result:

wrong answer 1st numbers differ - expected: '462334620', found: '462350212'

Test #9:

score: 0
Wrong Answer
time: 277ms
memory: 23892kb

input:

300000
728509094 406128756 696166390 756254976 31403187 672131182 35544213 870708756 3659210 5227553...

output:

464176898

result:

wrong answer 1st numbers differ - expected: '464162969', found: '464176898'

Test #10:

score: 0
Wrong Answer
time: 278ms
memory: 23888kb

input:

300000
804874490 52247250 546638789 400214210 383796618 47995083 814777769 507157584 466189162 28296...

output:

463577892

result:

wrong answer 1st numbers differ - expected: '463577194', found: '463577892'