#pragma GCC optimize("Ofast") #pragma GCC target("avx2") #define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);}) #define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;}) #define wt(v) {unsigned _z=v,_n=0;long _d=0;while(++_n,_d=_d<<8|0x30|_z%10,_z/=10);*(long*)wp=_d;wp+=_n;} #define rep(v,e) for(typeof(e) v=0;v<e;++v) #define reps(v,s,e) for(typeof(e) v=s;v<e;++v) char wbuf[1<<25]; int n; int p[200000]; int v[200001]; int s[200001]; void f1(){ rd_init(); n=rd(); rep(i,n){ p[i]=rd(); v[p[i]]=i; } } void f2(){ char*wp=wbuf; reps(a,1,n+1){ int i=v[a]; if(!s[i]){ int j,k; for(j=i+1;s[j];j=s[j]); for(k=i+1;s[k];k=s[k])s[k]=j; if(j<n){ wt(a); *wp++=' '; wt(p[j]); *wp++=' '; s[i]=s[j]=j+1; } } } write(1,wbuf,wp-wbuf); } int main(){ f1(); f2(); _exit(0); }