关于这道题的二分部分的疑惑

#include<bits/stdc++.h>

using namespace std;

inline int read(){
	int x = 0,f = 1;char c = getchar();
	for(;!isdigit(c);c = getchar())if( c == '-' )f = -1;
	for(;isdigit(c);c = getchar())x = ( x << 1 ) + ( x << 3 ) + c - '0';
	return x * f;
}

const int N = 1e6 + 5;
const int M = 1e3 + 5;

int n,m;
int a[N],belong[N],l[M],r[M],lazy[M],t[N],tot,len;

inline void build(){
	len = sqrt( n );
	tot = n / len;
	if(n % len)tot ++;
	for(int i = 1;i <= n;i ++){
		t[i] = a[i] = read();
		belong[i] = (i - 1) / len + 1;
	}
	for(int i = 1;i <= tot;i ++){
		l[i] = (i - 1) * len + 1;
		r[i] = i * len;
	}
	r[tot] = n;
	for(int i = 1;i <= tot;i ++)
		sort( t + l[i] , t + r[i] + 1 );
}

inline void change(int x,int y,int k){
	if( belong[x] == belong[y] ){
		for(int i = x;i <= y;i ++)a[i] += k;
		for(int i = l[belong[x]];i <= r[belong[x]];i ++)t[i] = a[i];
		sort( t + l[belong[x]] , t + r[belong[x]] + 1 );
	}
	else{
		for(int i = x;i <= r[belong[x]];i ++)a[i] += k;
		for(int i = l[belong[x]];i <= r[belong[x]];i ++)t[i] = a[i];
		sort( t + l[belong[x]] , t + r[belong[x]] + 1 );
		
		for(int i = l[belong[y]];i <= y;i ++)a[i] += k;
		for(int i = l[belong[y]];i <= r[belong[y]];i ++)t[i] = a[i];
		sort( t + l[belong[y]] , t + r[belong[y]] + 1 );
		
		for(int i = belong[x] + 1;i <= belong[y] - 1;i ++)lazy[i] += k;
	}
}


inline int query(int x,int y,int c){
	int ret = 0;
	if( belong[x] == belong[y] ){
		for(int i = x;i <= y;i ++)
			if( a[i] + lazy[belong[x]] >= c )ret ++;
		return ret;
	}	
	else{
		for(int i = x;i <= r[belong[x]];i ++){
			if( a[i] + lazy[belong[x]] >= c ){
				ret ++;
			}
		}
		for(int i = l[belong[y]];i <= y;i ++){
			if( a[i] + lazy[belong[y]] >= c ){
				ret ++;
			}
		}
		for(int i = belong[x] + 1;i <= belong[y] - 1;i ++){
			int L = l[i],R = r[i],mid;
			while( L < R ){
				mid = (L + R) >> 1;
				if( t[mid] + lazy[i] >= c )R = mid;
				else L = mid + 1;
			}
			ret += r[i] - L + 1;
		}
		return ret;
	}
}

signed main(){
	n = read();
	m = read();
	build();
	for(int i = 1;i <= m;i ++){
		char opt;
		cin >> opt;
		int x = read(),y = read(),w = read();
		if( opt == 'M' ){
			change( x , y , w );
		}
		else{
			int ans = query( x , y , w );
			printf("%d\n",ans);
		}
	}
	return 0;
}

#include<bits/stdc++.h>

using namespace std;

inline int read(){
	int x = 0,f = 1;char c = getchar();
	for(;!isdigit(c);c = getchar())if( c == '-' )f = -1;
	for(;isdigit(c);c = getchar())x = ( x << 1 ) + ( x << 3 ) + c - '0';
	return x * f;
}

const int N = 1e6 + 5;
const int M = 1e3 + 5;

int n,m;
int a[N],belong[N],l[M],r[M],lazy[M],t[N],tot,len;

inline void build(){
	len = sqrt( n );
	tot = n / len;
	if(n % len)tot ++;
	for(int i = 1;i <= n;i ++){
		t[i] = a[i] = read();
		belong[i] = (i - 1) / len + 1;
	}
	for(int i = 1;i <= tot;i ++){
		l[i] = (i - 1) * len + 1;
		r[i] = i * len;
	}
	r[tot] = n;
	for(int i = 1;i <= tot;i ++)
		sort( t + l[i] , t + r[i] + 1 );
}

inline void change(int x,int y,int k){
	if( belong[x] == belong[y] ){
		for(int i = x;i <= y;i ++)a[i] += k;
		for(int i = l[belong[x]];i <= r[belong[x]];i ++)t[i] = a[i];
		sort( t + l[belong[x]] , t + r[belong[x]] + 1 );
	}
	else{
		for(int i = x;i <= r[belong[x]];i ++)a[i] += k;
		for(int i = l[belong[x]];i <= r[belong[x]];i ++)t[i] = a[i];
		sort( t + l[belong[x]] , t + r[belong[x]] + 1 );
		
		for(int i = l[belong[y]];i <= y;i ++)a[i] += k;
		for(int i = l[belong[y]];i <= r[belong[y]];i ++)t[i] = a[i];
		sort( t + l[belong[y]] , t + r[belong[y]] + 1 );
		
		for(int i = belong[x] + 1;i <= belong[y] - 1;i ++)lazy[i] += k;
	}
}


inline int query(int x,int y,int c){
	int ret = 0;
	if( belong[x] == belong[y] ){
		for(int i = x;i <= y;i ++)
			if( a[i] + lazy[belong[x]] >= c )ret ++;
		return ret;
	}	
	else{
		for(int i = x;i <= r[belong[x]];i ++){
			if( a[i] + lazy[belong[x]] >= c ){
				ret ++;
			}
		}
		for(int i = l[belong[y]];i <= y;i ++){
			if( a[i] + lazy[belong[y]] >= c ){
				ret ++;
			}
		}
		for(int i = belong[x] + 1;i <= belong[y] - 1;i ++){
			int L = l[i],R = r[i],mid,res = 0;
			while( L <= R ){
				mid = (L + R) >> 1;
				if( t[mid] + lazy[i] >= c )R = mid - 1,res = r[i] - mid + 1;
				else L = mid + 1;
			}
			ret += res;
		}
		return ret;
	}
}

signed main(){
	n = read();
	m = read();
	build();
	for(int i = 1;i <= m;i ++){
		char opt;
		cin >> opt;
		int x = read(),y = read(),w = read();
		if( opt == 'M' ){
			change( x , y , w );
		}
		else{
			int ans = query( x , y , w );
			printf("%d\n",ans);
		}
	}
	return 0;
}