[USACO08NOV]lites

嘟嘟嘟

竟然还能发现这么水的题。就是线段树维护区间亦或嘛~~~~

 #include<cstdio>
 #include<iostream>
 #include<algorithm>
 #include<cmath>
 #include<cstring>
 #include<cstdlib>
 #include<stack>
 #include<queue>
 #include<vector>
 #include<cctype>
 using namespace std;
 #define space putchar(' ')
 #define enter puts("")
 #define Mem(a) memset(a, 0, sizeof(a))
 typedef long long ll;
 typedef double db;
 const int INF = 0x3f3f3f3f;
 const  db eps = 1e-;
 const int maxn = 1e5 + ;
 inline ll read()
 {
     ll ans = ;
     char ch = getchar(), last = ' ';
     while(!isdigit(ch)) {last = ch; ch = getchar();}
     while(isdigit(ch)) {ans = (ans << ) + (ans << ) + ch - ''; ch = getchar();}
     if(last == '-') ans = -ans;
     return ans;
 }
 inline void write(ll x)
 {
     if(x < ) putchar('-'), x = -x;
     if(x >= ) write(x / );
     putchar(x %  + '');
 }

 int n, m;

 int l[maxn << ], r[maxn << ], sum[maxn << ], lazy[maxn << ];
 void build(int L, int R, int now)
 {
     l[now] = L; r[now] = R;
     if(L == R) return;
     int mid = (L + R) >> ;
     build(L, mid, now << );
     build(mid + , R, now <<  | );
 }
 void pushdown(int now)
 {
     if(lazy[now])
     {
         sum[now << ] = r[now << ] - l[now << ] +  - sum[now << ];
         lazy[now << ] ^= ;
         sum[now <<  | ] = r[now <<  | ] - l[now <<  | ] +  - sum[now <<  | ];
         lazy[now <<  | ] ^= ;
         lazy[now] = ;
     }
 }
 void update(int L, int R, int now)
 {
     if(l[now] == L && r[now] == R)
     {
         sum[now] = (R - L + ) - sum[now];
         lazy[now] ^= ; return;
     }
     pushdown(now);
     int mid = (l[now] + r[now]) >> ;
     if(R <= mid) update(L, R, now << );
     else if(L > mid) update(L, R, now <<  | );
     else update(L, mid, now << ), update(mid + , R, now <<  | );
     sum[now] = sum[now << ] + sum[now <<  | ];
 }
 int query(int L, int R, int now)
 {
     if(l[now] == L && r[now] == R) return sum[now];
     pushdown(now);
     int mid = (l[now] + r[now]) >> ;
     if(R <= mid) return query(L, R, now << );
     else if(L > mid) return query(L, R, now <<  | );
     else return query(L, mid, now << ) + query(mid + , R, now <<  | );
 }

 int main()
 {
     n = read(); m = read();
     build(, n, );
     for(int i = ; i <= m; ++i)
     {
         int d = read(), L = read(), R = read();
         if(!d) update(L, R, );
         else write(query(L, R, )), enter;
     }
     return ;
 }