crf 的数数 （树状数组 离线操作）

crf 的数数

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#define N 1000010
#define LL long long
using namespace std;

int n, q, place
, a
;
int cnt
, ans;

inline int read(){
int x=0,f=1; char ch=getchar();
while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
return x*f;
}

struct data{
int l, r, id;
LL res;
}que
;

bool cmp(data a, data b){
if(place[a.l] == place[b.l]) return a.r < b.r;
return a.l < b.l;
}

bool recmp(data a, data b){
return a.id < b.id;
}

void update(int pos, int add){
cnt[a[pos]] += add;
if(cnt[a[pos]]-add == a[pos]) ans--;
if(cnt[a[pos]] == a[pos]) ans++;
}

void solve(){
for(register int i=1,l=1,r=0; i<=q; i++){
for( ; r<que[i].r; r++)
update(r+1, 1);
for( ; r>que[i].r; r--)
update(r, -1);
for( ; l<que[i].l; l++)
update(l, -1);
for( ; l>que[i].l; l--)
update(l-1, 1);
/*if(que[i].l == que[i].r){
que[i].a = 0;
continue;
}*/
que[i].res = ans;
}
}

int main(){
freopen ("count.in", "r", stdin);
freopen ("count.out", "w", stdout);
n = read(); q = read();
for(register int i=1; i<=n; i++) a[i] = read();
int block = int(sqrt(n));
for(register int i=1; i<=n; i++)
place[i] = (i-1) / block + 1;
for(register int i=1; i<=q; i++){
que[i].l = read(), que[i].r = read();
que[i].id = i;
}
sort(que+1, que+q+1, cmp);
solve();
sort(que+1, que+q+1, recmp);
for(register int i=1; i<=q; i++)
printf("%d\n", que[i].res);
return 0;
}

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

template<class T>inline void read(T &res) {
static char ch; T flag=1;
while((ch=getchar())<'0'||ch>'9')if(ch=='-')flag=-1;
res=ch-48;
while((ch=getchar())>='0'&&ch<='9')res=res*10+ch-48;
res*=flag;
}

const int N = 1000010;
const int Q = 1000010;

struct DATUM {
int x, y, delta;
bool operator<(const DATUM &rhs) const {
if(x!=rhs.x) return x<rhs.x;
if(y!=rhs.y) return y<rhs.y;
if(delta!=rhs.delta) return delta<rhs.delta;
}
} data[N*4+Q];

int tot, ans[Q];
int n, q, a
;

inline void addD(int x, int y, int delta) { data[++tot] = (DATUM){x, y, delta};}

void add(int pos, int val) { for(int x=pos; x<=n; x+=x&-x) a[x] += val;}
int query(int pos) {int val=0; for(int x=pos; x; x-=x&-x) val += a[x]; return val;}

pair<int, int> aa
;

int main() {
freopen("count.in", "r", stdin);
freopen("count.out", "w", stdout);
read(n); read(q);
for(register int i=1; i<=n; i++) read(aa[i].first), aa[i].second = i;
sort(aa+1, aa+n+1);//按照first排序
int siz = 0;
for(register int i=1; i<=n; i++) {
if(aa[i].first == aa[i-1].first) siz++;
else siz = 2, aa[i-siz+1].second = 0;
if(siz > aa[i].first) {
addD(aa[i-aa[i].first].second+1, aa[i].second, +1);
addD(aa[i-aa[i].first+1].second+1, aa[i].second, -1);
if(siz > aa[i].first + 1) addD(aa[i-aa[i].first-1].second+1, aa[i].second, -1);
if(siz > aa[i].first + 1) addD(aa[i-aa[i].first].second+1, aa[i].second, +1);
}
}
for(register int i=1,l,r; i<=q; i++) read(l), read(r), addD(l, r, i+1);
sort(data+1, data+tot+1);
for(register int i=1; i<=tot; i++) {
if(data[i].delta <= 1) add(data[i].y, data[i].delta);
else if(data[i].y>=1 && data[i].y<=n) ans[data[i].delta-1] = query(data[i].y);
}
for(register int i=1; i<=q; i++) printf("%d\n", ans[i]);
return 0;
}