这两天刚学树状数组的一点点部分，因为还在准备省赛，先贴代码好了
树状数组 1 ：单点修改，区间查询
1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<algorithm> 5 #include<cmath> 6 #include<queue> 7 #define pn putchar(' ') 8 #define pd putchar(' ') 9 #define num ch-'0' 10 #define reint register int 11 using namespace std; 12 template <typename T> 13 void read(T &res) 14 { 15 char ch;bool flag=false; 16 while(!isdigit(ch=getchar()))(ch=='-')&&(flag=true); 17 for(res=num;isdigit(ch=getchar());res=res*10+num); 18 flag&&(res=-res); 19 } 20 template <typename T> 21 void write(T x) 22 { 23 if(x<0)putchar('-'),x=-x; 24 if(x>9)write(x/10); 25 putchar(x%10+'0'); 26 } 27 typedef long long ll; 28 const int INF=0x7fffffff; 29 const int inf=0x3f3f3f3f; 30 const int mod=1000000007; 31 const int maxn=1000005; 32 ll tree[maxn],a[maxn]; 33 int n; 34 inline int lowbits(int x) { 35 return x&(-x); 36 } 37 inline void init(){ 38 for(int i=1;i<=n;i++) 39 read(a[i]); 40 for(int i=1;i<=n;i++) { 41 int lowb=lowbits(i); 42 for(reint j=i-lowb+1;j<=i;j++) 43 tree[i]+=a[j]; 44 } 45 } 46 inline void add(int p,ll v) { 47 for(int i=p;i<=n;i+=lowbits(i)) 48 tree[i]+=v; 49 } 50 inline ll getsum(int l,int r) { 51 ll ans1=0,ans2=0; 52 for(int i=l;i>=1;i-=lowbits(i)) 53 ans1+=tree[i]; 54 for(int i=r;i>=1;i-=lowbits(i)) 55 ans2+=tree[i]; 56 return ans2-ans1; 57 } 58 int main() 59 { 60 int q; 61 read(n);read(q); 62 init(); 63 while(q--) { 64 int oper,l,r,p; 65 ll v; 66 read(oper); 67 if(--oper) { 68 read(l),read(r); 69 write(getsum(l-1,r)); pn; 70 } 71 else { 72 read(p),read(v); 73 add(p,v); 74 } 75 } 76 return 0; 77 }
树状数组 2 ：区间修改，单点查询
1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<algorithm> 5 #include<cmath> 6 #include<queue> 7 #define pn putchar(' ') 8 #define pd putchar(' ') 9 #define num ch-'0' 10 #define reint register int 11 using namespace std; 12 template <typename T> 13 void read(T &res) 14 { 15 char ch;bool flag=false; 16 while(!isdigit(ch=getchar()))(ch=='-')&&(flag=true); 17 for(res=num;isdigit(ch=getchar());res=res*10+num); 18 flag&&(res=-res); 19 } 20 template <typename T> 21 void write(T x) 22 { 23 if(x<0)putchar('-'),x=-x; 24 if(x>9)write(x/10); 25 putchar(x%10+'0'); 26 } 27 typedef long long ll; 28 const int INF=0x7fffffff; 29 const int inf=0x3f3f3f3f; 30 const int mod=1000000007; 31 const int maxn=1000005; 32 int n; 33 ll d[maxn],tree[maxn]; 34 inline int lowbits(int x) { 35 return x&-x; 36 } 37 inline void init() { 38 ll a,b=0; 39 for(int i=1;i<=n;i++) { 40 read(a); 41 d[i]=a-b; 42 b=a; 43 } 44 for(int i=1;i<=n;i++) 45 for(int j=i-lowbits(i)+1;j<=i;j++) 46 tree[i]+=d[j]; 47 } 48 inline ll query(int p) { 49 ll ans=0; 50 while(p) ans+=tree[p],p-=lowbits(p); 51 return ans; 52 } 53 inline void add(int p,ll v) { 54 while(p<=n) { 55 tree[p]+=v; 56 p+=lowbits(p); 57 } 58 } 59 int main() 60 { 61 int q,oper; 62 read(n),read(q); 63 init(); 64 while(q--) { 65 read(oper); 66 if(--oper) { 67 int p; read(p); 68 write(query(p)),pn; 69 } 70 else { 71 int l,r; 72 ll v; 73 read(l),read(r),read(v); 74 add(l,v),add(r+1,-v); 75 } 76 } 77 return 0; 78 }