分块——入门8

这个题目很考验分块的思想了，如果一个块里面都是相同的数，就给这一整个块标记，再进行处理即可

//By Bibi
///                 .-~~~~~~~~~-._       _.-~~~~~~~~~-.
///             __.'              ~.   .~              `.__
///           .'//                  \./                  \\`.
///        .'//                     |                     \\`.
///       .'// .-~"""""""~~~~-._     |     _,-~~~~"""""""~-. \\`.
///     .'//.-"                 `-.  |  .-'                 "-.\\`.
///   .'//______.============-..   \ | /   ..-============.______\\`.
/// .'______________________________\|/______________________________`.
#include <bits/stdc++.h>
#define F(i, a, b) for (int i = (a); i < (b); ++i)
#define F2(i, a, b) for (int i = (a); i <= (b); ++i)
#define maxn 100010
#define maxm 1010
using namespace std;
int a[maxn],bl[maxn],n,blo,tag[maxm];
bool flag[maxm];
int read()
{
    int sum=0,flag=1;
    char c;
    for(;c<'0'||c>'9';c=getchar())if(c=='-') flag=-1;
    for(;c>='0'&&c<='9';c=getchar())sum=(sum<<1)+(sum<<3)+c-'0';
    return sum*flag;
}
void reset(int p) 
{
    if (!flag[p]) return;
    flag[p]=false;
    F(i,p*blo,min(n,(p+1)*blo)) a[i]=tag[p];
}
int query(int l,int r,int c) 
{
    int ret=0;
    if (flag[bl[l]]&&tag[bl[l]]==c) ret+=min(r+1,(bl[l]+1)*blo)-l;
    else 
    {
        reset(bl[l]);
        F(i,l,min(r+1,(bl[l]+1)*blo)) 
        {
            ret+=a[i]==c;
            a[i]=c;
        }
    }
    if (bl[l]!=bl[r]) 
    {
        if (flag[bl[r]]&&tag[bl[r]]==c) ret+=r-bl[r]*blo+1;
        else 
        {
            reset(bl[r]);
            F2(i,bl[r]*blo,r) 
            {
                ret+=a[i]==c;
                a[i]=c;
            }
        }
    }
    F(i,bl[l]+1,bl[r]) 
    {
        if (flag[i]) 
        {
            if (tag[i]==c) ret+=blo;
        }
        else 
        {
            flag[i]=true;
            F(j,i*blo,(i+1)*blo) ret+=a[j]==c;
        }
        tag[i]=c;
    }
    return ret;
}
int main() 
{
    n=read();
    blo=sqrt(n);
    F(i,0,n) 
    {
        a[i]=read();
        bl[i]=i/blo;
    }
    int num=(n+blo-1)/blo;
    F(i,0,n) 
    {
        int l,r,c;
        l=read();r=read();c=read();  --l, --r;
        printf("%d\n",query(l,r,c));
    }
    return 0;
}