題目鏈接

luogu P4688 [Ynoi2016]掉進兔子洞

題解

莫隊維護bitset區間交個數

代碼

// luogu-judger-enable-o2
#include<cmath> 
#include<bitset> 
#include<cstdio> 
#include<cstring> 
#include<algorithm> 
inline int read() {     
    int x = 0,f = 1; 
    char c = getchar(); 
    while(c < '0' || c > '9') {if(c == '-')f = -1 ; c = getchar(); } 
    while(c <= '9' && c >= '0') x = x * 10 + c - '0', c = getchar(); 
    return x * f; 
} 
const int whattt = 20001; 
const int maxn = 100007; 
int a[maxn],bel[maxn],b[maxn]; 
int l1[maxn],r1[maxn],l2[maxn],r2[maxn],l3[maxn],r3[maxn]; 
int sum[maxn]; 
int n,m,k; 
struct Que { 
    int l,r,id; 
     Que(int l = 0,int r = 0,int id = 0) :l (l),r (r),id (id){}; 
     bool operator < (const Que & a) const {
            if(bel[l] == bel[a.l]) return r < a.r; 
            return bel[l] < bel[a.l]; 
    } 
} q[33334 * 3 + 7]; 
std::bitset<100000> F[whattt + 7],f; 
bool mark[33334 + 7]; 
int len; 
int cnt[maxn],c[whattt * 3 + 7]; 
void update(int k,int ty) { 
    k = a[k]; cnt[k] += ty; 
    if(ty == 1) f[k + cnt[k] - 2] = 1; 
    else f[k + cnt[k] - 1] = 0; 
} 
void solve() { 
    memset(mark,0,sizeof mark); 
    memset(cnt,0,sizeof(cnt)); 
    std::sort(q + 1,q + len + 1); 
    int l = 1,r = 0; 
    f.reset(); 
    for(int i = 1;i <= len;++ i) { 
        while(r < q[i].r) update(++ r,1); 
        while(r > q[i].r) update(r --,-1); 
        while(l < q[i].l) update(l ++,-1); 
        while(l > q[i].l) update(-- l,1); 
        if(mark[q[i].id])F[q[i].id] &= f,c[q[i].id] = F[q[i].id].count(); 
        else F[q[i].id] = f,mark[q[i].id] = 1; 
    } 
} 
int main() { 
    //freopen("xp1.in","r",stdin); 
    n = read(),m = read(); 
    k = sqrt(n); 
    for(int i = 1;i <= n;++ i) b[i] = a[i] = read(),bel[i] = (i - 1) / k + 1; 
    std::sort(b + 1,b + n +1); 
    len = n; 
    for(int i = 1;i <= n;++ i) a[i] = std::lower_bound(b + 1,b + len + 1,a[i]) - b; 
    for(int i = 1;i <= m;i += 1) { 
        l1[i] = read(),r1[i] = read(),l2[i] = read(),r2[i] = read(),l3[i] = read(),r3[i] = read(); 
        sum[i] = r1[i] - l1[i] + 1 + r2[i] - l2[i] + 1 + r3[i] - l3[i] + 1; 
    } 
    for(int i = 1;i <= m;i += whattt) { 
        len = 0; 
        for(int j = i;j <= i + whattt - 1; ++ j) { 
            if(j > m) break; 
            q[++ len] = Que(l1[j],r1[j],j - i + 1); 
            q[++ len] = Que(l2[j],r2[j],j - i + 1); 
            q[++ len] = Que(l3[j],r3[j],j - i + 1); 
        } 
        solve(); 
        for(int j = i;j < i + whattt; ++ j) { 
            if(j > m) break; 
            printf("%d\n",sum[j] - 3 * c[j - i + 1]); 
            //return 0; 
        } 
    } 
    return 0; 
} 
 

luogu P4688 [Ynoi2016]掉進兔子洞 bitset 莫隊