hdu 1166敵兵布陣(線段樹或者樹狀數組)

http://acm.hdu.edu.cn/showproblem.php?pid=1166

不懂得可以看劉汝佳訓練指南P194

//線段樹版：#include <iostream>#include <cstdio> #include <cstring>using namespace std;int n,s[50005*4];void update(int id,int d,int L,int R,int O){int M=L+(R-L)/2;if(L==R) s[O]+=d;else{if(id<=M) update(id,d,L,M,O*2); else update(id,d,M+1,R,O*2+1);s[O]=s[O*2]+s[O*2+1];}}int query(int ql,int qr,int L,int R,int O){int M=L+(R-L)/2,ans=0;if(ql<=L&&R<=qr) return s[O];if(ql<=M) ans+=query(ql,qr,L,M,O*2);if(M<qr)  ans+=query(ql,qr,M+1,R,O*2+1);return ans;}int main(int argc, char *argv[]){    int t,i,d,k=1; char a[10];    scanf("%d",&t);    while(t--!=0)    {        printf("Case %d:\n",k++);            scanf("%d",&n);            memset(s,0,sizeof(s));            for(i=1;i<=n;i++)            {                scanf("%d",&d); update(i,d,1,n,1);            }                while(scanf("%s",a))            {                if(a[0]=='E') break;                scanf("%d%d",&i,&d);                if(a[0]=='Q') printf("%d\n",query(i,d,1,n,1));                else if(a[0]=='A') update(i,d,1,n,1);                else if(a[0]=='S') update(i,-d,1,n,1);            }        }    return 0;}

//樹狀數組版：#include <iostream>#include <cstdio> #include <cstring>using namespace std;int n,s[50005];int LowBit(int x){    return x&-x;  }void Add(int x,int d){    while(x<=n)    {  s[x]+=d;  x+=LowBit(x);}}int Sum(int x){    int ans=0;    while(x>0)    {    ans+=s[x];  x-=LowBit(x); }    return ans;}int main(int argc, char *argv[]){    int t,i,d,k=1; char a[10];    scanf("%d",&t);    while(t--!=0)    {        printf("Case %d:\n",k++);            scanf("%d",&n);            memset(s,0,sizeof(s));            for(i=1;i<=n;i++)            {                scanf("%d",&d); Add(i,d);            }                while(scanf("%s",a))            {                if(a[0]=='E') break;                scanf("%d%d",&i,&d);                if(a[0]=='Q') printf("%d\n",Sum(d)-Sum(i-1));                else if(a[0]=='A') Add(i,d);                else if(a[0]=='S') Add(i,-d);            }        }    return 0;}