好好学一下线段树----
从0开始----加油～
单点更新的
1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<algorithm> 5 #include<cmath> 6 #include<vector> 7 using namespace std; 8 #define lp (p << 1) 9 #define rp (p << 1 | 1) 10 #define getmid(l,r) (l + (r - l) / 2) 11 12 const int maxn = 50005; 13 struct node{ 14 int l,r,s; 15 }t[4*maxn]; 16 17 int a[maxn],n; 18 19 int calc(int a,int b) { return a+b; } 20 21 void Push_up(int p){ 22 t[p].s = calc(t[lp].s,t[rp].s); 23 } 24 25 void Build_tree(int p,int l,int r){ 26 t[p].l = l; 27 t[p].r = r; 28 if(l == r){ t[p].s = a[l];return;} 29 int mid = getmid(l,r); 30 Build_tree(lp,l,mid); 31 Build_tree(rp,mid+1,r); 32 Push_up(p); 33 } 34 35 void update(int p,int s,int w){//给s点加上w 36 if(t[p].l == t[p].r) { 37 t[p].s += w; 38 return; 39 } 40 int mid = getmid(t[p].l,t[p].r); 41 if(s <= mid) update(lp,s,w); 42 else update(rp,s,w); 43 Push_up(p); 44 } 45 46 int sum(int p,int l,int r){ 47 if(t[p].l == l && t[p].r == r) return t[p].s; 48 49 int mid = getmid(t[p].l,t[p].r); 50 if(r <= mid) return sum(lp,l,r); 51 else if(mid < l) return sum(rp,l,r); 52 else return calc(sum(lp,l,mid),sum(rp,mid+1,r)); 53 } 54 55 int main(){ 56 int T; 57 scanf("%d",&T); 58 int kase = 0; 59 while(T--){ 60 scanf("%d",&n); 61 for(int i = 1;i <= n;i++) scanf("%d",&a[i]); 62 Build_tree(1,1,n); 63 64 // for(int i = 1;i <= n;i++) 65 // printf("t[%d].l = %d t[%d].r = %d t[%d].s = %d ",i,t[i].l,i,t[i].r,i,t[i].s); 66 67 char cmd[10]; 68 int x,y; 69 printf("Case %d: ",++kase); 70 while(cin >> cmd){ 71 if(cmd[0] == 'E') break; 72 else if(cmd[0] == 'A'){ 73 scanf("%d %d",&x,&y); 74 update(1,x,y); 75 } 76 else if(cmd[0] == 'S'){ 77 scanf("%d %d",&x,&y); 78 update(1,x,-y); 79 } 80 else{ 81 scanf("%d %d",&x,&y); 82 printf("%d ",sum(1,x,y)); 83 } 84 } 85 } 86 return 0; 87 }