var

f,a:array[0..100000] of longint;

n,i,k,p,ans,j:longint;

begin

readln(n);

for i:=1 to n do read(a[i]);readln;

readln(k);

for i:=1 to n do{记录有多少比K小的}

if a[i]<k then f[i]:=f[i-1]+1

else begin

f[i]:=f[i-1];

if a[i]=k then p:=i;{K的位置}

end;

for i:=1 to p do{枚举(1,P)与(P,n)的组合}

begin

j:=p; if (j-i) mod 2<>0 then inc(j);{保证(i~j)为奇数}

repeat

if f[j]-f[i-1]>(j-i)div 2 then j:=2*(f[j]-f[i-1])+i{p~n间最小的可能解(貌似错了,改成inc(j)有几组数据能对,又有几组会错)}

else if f[j]-f[i-1]<(j-i)div 2 then j:=2*(j-i-f[j]+f[i])+i{p~n间最小的可能解(貌似错了,改成inc(j)有几组数据能对,又有几组会错)}

else begin inc(ans);inc(j);end;{f[j]-f[i-1]=(j-i)div 2比K大的和比K小的相等,得解}

if (j-i)mod 2<>0 then inc(j);{保证(i~j)为奇数}

until j>n;

end;

writeln(ans);

end.

希望有大牛能找出错误来,做了N久,无语了~~

总算是过了....

program RQEX_500;

var

f,a:array[0..100000] of longint;

n,i,k,p,ans,j:longint;

begin

readln(n);

for i:=1 to n do read(a[i]);readln;

readln(k);

for i:=1 to n do

if a[i]<k then f[i]:=f[i-1]+1

else begin

f[i]:=f[i-1];

if a[i]=k then p:=i;

end;

for i:=1 to p do

begin

j:=p; if (j-i) mod 2<>0 then inc(j);

repeat

if f[j]-f[i-1]=(j-i)div 2 then inc(ans)

else begin

j:=abs(j-i-2*(f[j]-f[i-1]))+j-2;

if (j-i)mod 2<>0 then inc(j);

end;

j:=j+2;

until j>n;

end;

writeln(ans);

end.