#include<cstdio>
#include<cstring>
const int maxn=100010;
#define lowbit(i) ((i)&(i))
int c[maxn];
void update(int x,int v) {
for(int i=x;i<maxn;i+=lowbit(i)) {
c[i]+=v;
}
}
int getsum(int x) {
int sum=0;
for(int i=x;i>=;i-=lowbit(i)) {
sum+=c[i];
}
return sum;
}
线段树的基本运算
原文：https://www.cnblogs.com/superPG/p/12298097.html
