一维树状数组
单点更新,区间查询
void update(int x,int y,int n){
for(int i=x;i<=n;i+=lowbit(i)) //x为更新的位置,y为更新后的数,n为数组最大值
c[i] += y;
}
int getsum(int x){
int ans = 0;
for(int i=x;i;i-=lowbit(i))
ans += c[i];
return ans;
}
区间修改,单点查询
void add(int p, int x){ //这个函数用来在树状数组中直接修改
while(p <= n) sum[p] += x, p += p & -p;//sum[]为原数组的差分数组
}
void range_add(int l, int r, int x){ //给区间[l, r]加上x
add(l, x), add(r + 1, -x);
}
int ask(int p){ //单点查询
int res = 0;
while(p) res += sum[p], p -= p & -p;
return res;
}
区间修改,区间查询
void add(ll p, ll x){
for(int i = p; i <= n; i += i & -i)
sum1[i] += x, sum2[i] += x * p;//sum1[]为原数组的差分数组
}
void range_add(ll l, ll r, ll x){
add(l, x), add(r + 1, -x);
}
ll ask(ll p){
ll res = 0;
for(int i = p; i; i -= i & -i)
res += (p + 1) * sum1[i] - sum2[i];
return res;
}
ll range_ask(ll l, ll r){
return ask(r) - ask(l - 1);
}
二维树状数组
单点修改+区间查询
void add(int x, int y, int z){ //将点(x, y)加上z
int memo_y = y;
while(x <= n){
y = memo_y;
while(y <= n)
tree[x][y] += z, y += y & -y;
x += x & -x;
}
}
int ask(int x, int y){//求左上角为(1,1)右下角为(x,y) 的矩阵和
int res = 0, memo_y = y;
while(x){
y = memo_y;
while(y)
res += tree[x][y], y -= y & -y;
x -= x & -x;
}
return res;
}
区间修改+单点查询
void add(int x, int y, int z){
int memo_y = y;
while(x <= n){
y = memo_y;
while(y <= n)
tree[x][y] += z, y += y & -y;
x += x & -x;
}
}
void range_add(int xa, int ya, int xb, int yb, int z){
add(xa, ya, z);
add(xa, yb + 1, -z);
add(xb + 1, ya, -z);
add(xb + 1, yb + 1, z);
}
int ask(int x, int y){
int res = 0, memo_y = y;
while(x){
y = memo_y;
while(y)
res += tree[x][y], y -= y & -y;
x -= x & -x;
}
return res;
}
区间修改+区间查询
void add(ll x, ll y, ll z){
for(int X = x; X <= n; X += X & -X)
for(int Y = y; Y <= m; Y += Y & -Y){
t1[X][Y] += z;
t2[X][Y] += z * x;
t3[X][Y] += z * y;
t4[X][Y] += z * x * y;
}
}
void range_add(ll xa, ll ya, ll xb, ll yb, ll z){ //(xa, ya) 到 (xb, yb) 的矩形
add(xa, ya, z);
add(xa, yb + 1, -z);
add(xb + 1, ya, -z);
add(xb + 1, yb + 1, z);
}
ll ask(ll x, ll y){
ll res = 0;
for(int i = x; i; i -= i & -i)
for(int j = y; j; j -= j & -j)
res += (x + 1) * (y + 1) * t1[i][j]
- (y + 1) * t2[i][j]
- (x + 1) * t3[i][j]
+ t4[i][j];
return res;
}
ll range_ask(ll xa, ll ya, ll xb, ll yb){
return ask(xb, yb) - ask(xb, ya - 1) - ask(xa - 1, yb) + ask(xa - 1, ya - 1);
}
参考博客:https://blog.youkuaiyun.com/bestsort/article/details/80796531