HDU 1166 敌兵布阵【线段树 单点更新】

  1 #include<iostream>  
  2 #include<cstdio>  
  3 #include<cstring> 
  4 #include <cmath> 
  5 #include<stack>
  6 #include<vector>
  7 #include<map> 
  8 #include<set>
  9 #include<queue> 
 10 #include<algorithm>  
 11 using namespace std;
 12 
 13 typedef long long LL;
 14 const int INF = (1<<30)-1;
 15 const int mod=1000000007;
 16 const int maxn=1000005;
 17 
 18 int a[maxn];
 19 
 20 struct node{
 21     int l,r;
 22     int s;
 23 };
 24 
 25 node tree[4*maxn];
 26 
 27 int calc(int x,int y) { return x + y;}
 28 
 29 void build_tree(int i,int l,int r){
 30     if(l==r){
 31         tree[i].l=l;
 32         tree[i].r=r;
 33         tree[i].s=a[l];
 34         return;
 35     }
 36     int mid=(l+r)/2;
 37     build_tree(2*i,l,mid);
 38     build_tree(2*i+1,mid+1,r);
 39     tree[i].l=l;
 40     tree[i].r=r;
 41     tree[i].s=calc(tree[2*i].s,tree[2*i+1].s);
 42 }
 43 
 44 void update1(int i,int s,int w){
 45     if(tree[i].l==tree[i].r){
 46         tree[i].s+=w;
 47         return;
 48     }
 49     int mid=(tree[i].l + tree[i].r)/2;
 50     if(s<=mid) update1(2*i,s,w);
 51     else update1(2*i+1,s,w);
 52     
 53     tree[i].s=calc(tree[2*i].s,tree[2*i+1].s);
 54 }
 55 
 56 void update2(int i,int s,int w){
 57     if(tree[i].l==tree[i].r){
 58         tree[i].s-=w;
 59         return;
 60     }
 61     int mid=(tree[i].l + tree[i].r)/2;
 62     if(s<=mid) update2(2*i,s,w);
 63     else update2(2*i+1,s,w);
 64     
 65     tree[i].s=calc(tree[2*i].s,tree[2*i+1].s);
 66 }
 67 
 68 int sum(int i,int l,int r){
 69 //    printf("tree[%d].s=%d\n",i,tree[i].s);
 70     if(tree[i].l==l&&tree[i].r==r){
 71         return tree[i].s;
 72     }
 73     else{
 74         int mid=(tree[i].l+tree[i].r)/2;
 75         if(r<=mid) return sum(2*i,l,r);
 76         if(l>mid) return sum(2*i+1,l,r);
 77     
 78         return calc(sum(2*i,l,mid),sum(2*i+1,mid+1,r));
 79     }
 80 }
 81 
 82 int main(){
 83     int T;
 84     scanf("%d",&T);
 85     int kase=0;
 86     while(T--){
 87         int n;
 88         scanf("%d",&n);
 89         for(int i=1;i<=n;i++) scanf("%d",&a[i]);
 90         
 91         build_tree(1,1,n);
 92         
 93             char s[15];
 94         int x,y;
 95         printf("Case %d:\n",++kase);
 96         
 97         while(scanf("%s",s)!=EOF){
 98             
 99             if(s[0] == ‘E‘) break;
100             if(s[0] == ‘A‘){
101                 scanf("%d %d",&x,&y);
102                 update1(1,x,y);
103             }
104             if(s[0]==‘S‘){
105                 scanf("%d %d",&x,&y);
106                 update2(1,x,y);
107             }
108             if(s[0] == ‘Q‘){
109                 scanf("%d %d",&x,&y);
110                 printf("%d\n",sum(1,x,y));
111             }
112         }    
113     }
114     return 0;
115 }