zufesatoshi的博客

树状数组写法 class Solution { public: #define maxn 50050 #define lowbit(i) (i&(-i)) int n, m, a[maxn], b[maxn], c[maxn]; void update(int x){ for(int i = x ; i <= m ; i += lowbit(i)) c[i] ++; return; } int query(int