Segment Tree interval update + interval merging

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One look is the problem of merging the segment tree interval.

Two operations, one with the new, one query

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include < iostream> #include <algorithm> #include <stack> #include <queue> #include <string> #include
<vector> #include <set> #include <map> #include <string> using namespace std;
typedef long Long LL;
const int inf=0x3f3f3f3f;
Char str[1000010];
    struct Node1 {int l,r,len,lazy;
    int LB,RB,MB;
        void Merge (int key) {if (key==1) {lb=rb=mb=0;}
    else {Lb=rb=mb=len;}
}}node[1000010*4];
    void push_up (int n) {int lson=n*2,rson=n*2+1;
    node[n].lb=node[lson].lb;
    NODE[N].RB=NODE[RSON].RB;
    if (Node[lson].lb==node[lson].len) node[n].lb+=node[rson].lb;
    if (Node[rson].rb==node[rson].len) node[n].rb+=node[lson].rb;
Node[n].mb=max (Max (NODE[RSON].MB,NODE[LSON].MB), node[lson].rb+node[rson].lb);
        } void Push_down (int n) {if (node[n].lazy) {node[n*2].lazy=node[n*2+1].lazy=node[n].lazy; node[N*2]. Merge (Node[n].lazy); node[n*2+1].
        Merge (Node[n].lazy);
    node[n].lazy=0;
    }} void Build (int l,int r,int n) {node[n].l=l,node[n].r=r,node[n].len=r-l+1,node[n].lazy=0;
        if (l==r) {if (str[l]== ' A ') node[n].lb=node[n].rb=node[n].mb=0;
        else if (str[l]== ' B ') node[n].lb=node[n].rb=node[n].mb=1;
    Return
    } int mid= (L+R)/2;
    Build (L,MID,N*2);
    Build (mid+1,r,n*2+1);
PUSH_UP (n); } void Update (int p,int q,int n,int k) {if (P&LT;=NODE[N].L&AMP;&AMP;Q&GT;=NODE[N].R) {node[n].lazy=k;node[n].
    Merge (k); return;}
    Push_down (n);
    int mid= (NODE[N].L+NODE[N].R)/2;
    if (p>=mid+1) update (P,Q,N*2+1,K);
    else if (q<=mid) update (P,Q,N*2,K);
    Else{update (p,q,n*2,k); update (p,q,n*2+1,k);}
PUSH_UP (n);
    } node1 merge_query (Node1 p1,node1 p2) {node1 ans;
    Ans.len=p1.len+p2.len;
    ANS.LB=P1.LB;ANS.RB=P2.RB;
    if (P1.lb==p1.len) ans.lb+=p2.lb;
    if (P2.rb==p2.len) ans.rb+=p1.rb; Ans.mb=max (Max (P1.MB,P2.MB), P1.RB+P2.Lb);
return ans;
    } node1 Query (int p,int q,int N) {if (NODE[N].L&GT;=P&AMP;&AMP;Q&GT;=NODE[N].R) return node[n];
    Push_down (n);
    int mid= (NODE[N].L+NODE[N].R)/2;
    if (p>=mid+1) return query (p,q,n*2+1);
    else if (q<=mid) return query (P,Q,N*2);
else{return merge_query (Query (p,q,n*2), query (p,q,n*2+1));}}
    int main () {int t;scanf ("%d", &t);
        for (int ca=1;ca<=t;ca++) {printf ("Case #%d:\n", CA); int n,m;
        scanf ("%d%d", &n,&m); scanf ("%s", str+1);
        Build (1,n,1);
            while (m--) {int op,l,r,w;scanf ("%d%d%d", &op,&l,&r);
            if (op==1) {scanf ("%d", &w); update (L,R,1,W);}
                else {Node1 ans=query (l,r,1);
            printf ("%d\n", Max (Ans.lb,max (ANS.RB,ANS.MB)));
}}} return 0;
 }