XOR的藝術[線段樹]
阿新 • • 發佈:2018-11-24
全部異或1 就是區間值變為區間長度-當前值 , 打一個tag就好
#include<bits/stdc++.h> #define N 200050 #define len (t[x].r-t[x].l+1) #define Llen (t[x<<1].r-t[x<<1].l+1) #define Rlen (t[x<<1|1].r-t[x<<1|1].l+1) using namespace std; int a[N],n,m; char s[N]; struct Node{int l,r,val,tag;}t[N<<2]; void Pushup(int x){t[x].val = t[x<<1].val + t[x<<1|1].val;} void build(int x,int l,int r){ t[x].l = l , t[x].r = r; if(l==r){t[x].val = a[l]; return;} int mid = (l+r)>>1; build(x<<1,l,mid) , build(x<<1|1,mid+1,r); Pushup(x); } void Pushdown(int x){ if(t[x].tag){ t[x<<1].val = Llen - t[x<<1].val; t[x<<1|1].val = Rlen - t[x<<1|1].val; t[x<<1].tag ^= 1; t[x<<1|1].tag ^= 1; t[x].tag = 0; } } void update(int x,int L,int R){ if(L<=t[x].l && t[x].r<=R){ t[x].val = len - t[x].val; t[x].tag ^= 1; return; } Pushdown(x); int mid = (t[x].l+t[x].r)>>1; if(L<=mid) update(x<<1,L,R); if(R>mid) update(x<<1|1,L,R); Pushup(x); } int quary(int x,int L,int R){ if(L<=t[x].l && t[x].r<=R) return t[x].val; Pushdown(x); int mid = (t[x].l+t[x].r)>>1 , ans=0; if(L<=mid) ans += quary(x<<1,L,R); if(R>mid) ans += quary(x<<1|1,L,R); return ans; } int main(){ scanf("%d%d%s",&n,&m,s); for(int i=0;i<n;i++) a[i+1] = s[i]-'0'; build(1,1,n); while(m--){ int op,x,y; scanf("%d%d%d",&op,&x,&y); if(op==0) update(1,x,y); if(op==1) printf("%d\n",quary(1,x,y)); }return 0; }