結果
問題 | No.1300 Sum of Inversions |
ユーザー | snow39 |
提出日時 | 2020-11-27 21:44:04 |
言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 423 ms / 2,000 ms |
コード長 | 4,147 bytes |
コンパイル時間 | 1,603 ms |
コンパイル使用メモリ | 114,980 KB |
実行使用メモリ | 20,080 KB |
最終ジャッジ日時 | 2024-07-26 12:06:21 |
合計ジャッジ時間 | 13,025 ms |
ジャッジサーバーID (参考情報) |
judge5 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 34 |
ソースコード
#include <iostream>#include <algorithm>#include <string>#include <vector>#include <cmath>#include <map>#include <queue>#include <iomanip>#include <set>#include <tuple>#define mkp make_pair#define mkt make_tuple#define rep(i,n) for(int i = 0; i < (n); ++i)#define all(v) v.begin(),v.end()using namespace std;typedef long long ll;const ll MOD=998244353;template<class T> void chmin(T &a,const T &b){if(a>b) a=b;}template<class T> void chmax(T &a,const T &b){if(a<b) a=b;}#include <functional>#include <climits>//SegmentTree<int> seg(N,[](int a,int b){return min(a,b);},INT_MAX);template< typename T>class SegmentTree{private:void resize(int size){n=1;while(n<size) n*=2;tree.resize(2*n-1,def);}public:using F = function<T(T,T)>;int n;vector<T> tree;F operation;T def;SegmentTree(){}SegmentTree(int size,F _operation,T _def):operation(_operation),def(_def){resize(size);}void embody(int size,F _operation,T _def){operation=_operation;def=_def;resize(size);}void initialize(const vector<T> &v){int size=v.size();resize(size);for(int i=0;i<size;i++) tree[i+n-1]=v[i];for(int i=n-2;i>=0;i--) tree[i]=operation(tree[2*i+1],tree[2*i+2]);}void update(int index,T value){index+=n-1;tree[index]=value;while(index>0){index=(index-1)/2;tree[index]=operation(tree[2*index+1],tree[2*index+2]);}}T query(int a,int b,int k=0,int l=0,int r=-1){//[a,b)if(r<0) r=n;if(r<=a||b<=l) return def;else if(a<=l&&r<=b) return tree[k];else{T lval=query(a,b,2*k+1,l,(l+r)/2);T rval=query(a,b,2*k+2,(l+r)/2,r);return operation(lval,rval);}}T get(int index){return tree[index+n-1];}int find(int x,int k=0,int l=0,int r=-1){// a[0]+...+a[i]>=x (i:minimal)if(r<0) r=n;if(tree[k]<x) return -1;if(r-l==1) return k-(n-1);if(tree[2*k+1]>=x) return find(x,2*k+1,l,(l+r)/2);else return find(x-tree[2*k+1],2*k+2,(l+r)/2,r);}//right -> change vl to vr (notice doesn't contain b. range [a,b))int find_left(int a,int b,T x,int k=0,int l=0,int r=-1){// max(a[a],...,a[i])>=x (i:minimal)if(r<0) r=n;if(tree[k]<x||r<=a||b<=l) return -1;if(r-l==1) return k-(n-1);int vl=find_left(a,b,x,2*k+1,l,(l+r)/2);if(vl>=0) return vl;return find_left(a,b,x,2*k+2,(l+r)/2,r);}};ll mod_pow(ll x,ll n){x%=MOD;ll res=1;while(n>0){if(n&1) res=res*x%MOD;x=x*x%MOD;n>>=1;}return res;}ll mod_inverse(ll x){return mod_pow(x,MOD-2);}void add(ll &a,ll b){a=(a+b)%MOD;}void mul(ll &a,ll b){a%=MOD;b%=MOD;a=a*b%MOD;}int main(){cin.tie(0);ios::sync_with_stdio(false);int N;cin>>N;vector<ll> A(N);rep(i,N) cin>>A[i];vector<ll> leftNum(N,0),rightNum(N,0);vector<ll> leftSum(N,0),rightSum(N,0);{SegmentTree<pair<ll,ll>> seg(N,[](pair<ll,ll> a,pair<ll,ll> b){return mkp(a.first+b.first,a.second+b.second);},mkp(0ll,0ll));vector<int> ord(N,0);rep(i,N) ord[i]=i;sort(all(ord),[&](int a,int b){if(A[a]!=A[b]) return A[a]>A[b];else return a>b;});for(auto i:ord){auto f=seg.query(0,i);leftNum[i]=f.second;leftSum[i]=f.first%MOD;seg.update(i,mkp(A[i],1));}}{SegmentTree<pair<ll,ll>> seg(N,[](pair<ll,ll> a,pair<ll,ll> b){return mkp(a.first+b.first,a.second+b.second);},mkp(0ll,0ll));vector<int> ord(N,0);rep(i,N) ord[i]=i;sort(all(ord),[&](int a,int b){if(A[a]!=A[b]) return A[a]<A[b];else return a<b;});for(auto i:ord){auto f=seg.query(i,N);rightNum[i]=f.second;rightSum[i]=f.first%MOD;seg.update(i,mkp(A[i],1));}}ll ans=0;for(int j=0;j<N;j++){if(leftNum[j]==0||rightNum[j]==0) continue;ll ares=leftSum[j]*rightNum[j]%MOD;ll bres=rightSum[j]*leftNum[j]%MOD;ll res=leftNum[j]*rightNum[j]%MOD*A[j]%MOD;add(res,ares);add(res,bres);add(ans,res);}cout<<ans<<endl;return 0;}