题目链接
题意:
题解:
AC代码
/* Author:zzugzx Lang:C++ Blog:blog.csdn.net/qq_43756519 */ #include<bits/stdc++.h> using namespace std; #define fi first #define se second #define pb push_back #define mp make_pair #define all(x) (x).begin(),(x).end() #define endl '\n' typedef long long ll; typedef pair<int, int> pii; typedef pair<ll, ll> pll; const int mod=1e9+7; //const int mod=998244353; const double eps = 1e-10; const double pi=acos(-1.0); const int maxn=1e6+10; const ll inf=0x3f3f3f3f; const int dir[4][2]={{0,1},{1,0},{0,-1},{-1,0}}; int a[maxn]; int main() { ios::sync_with_stdio(false); cin.tie(0);cout.tie(0); //freopen("in.txt","r",stdin); //freopen("out.txt","w",stdout); int n,b; cin>>n>>b; map<int,int> m; int pos; for(int i=1;i<=n;i++){ cin>>a[i]; if(a[i]==b)pos=i; } int sum=0,ans=1; m[0]++; for(int i=pos-1;i;i--){ if(a[i]>b)sum--; else sum++; if(sum==0)ans++; m[sum]++; } sum=0; for(int i=pos+1;i<=n;i++){ if(a[i]>b)sum--; else sum++; ans+=m[-sum]; } cout<<ans; return 0; }