題目鏈接：http://acm.hdu.edu.cn/showPRoblem.php?pid=1166 題意：中文題 解析：線段樹，單點更新，單點查詢
#include <bits/stdc++.h>using namespace std;const int maxn = 50000+100;struct node{ int l,r; int sum;}tree[4* maxn];int a[maxn];void push_up(int i){ tree[i].sum = tree[i<<1].sum + tree[i<<1|1].sum;}void build(int i,int l,int r){ tree[i].l = l,tree[i].r = r; tree[i].sum = 0; if(l==r) { tree[i].sum = a[l]; return ; } int mid = (l+r)>>1; build(i<<1,l,mid); build(i<<1|1,mid+1,r); push_up(i);}void update(int i,int pos,int val){ int l = tree[i].l; int r = tree[i].r; if(l==pos && r==pos) { tree[i].sum += val; return ; } int mid = (l+r)>>1; if(mid>=pos) update(i<<1,pos,val); else update(i<<1|1,pos,val); push_up(i);}int query(int i,int l,int r){ int L = tree[i].l; int R = tree[i].r; if(l<=L && R<=r) return tree[i].sum; int mid = (L+R)>>1; int ans = 0; if(mid<r) ans += query(i<<1|1,l,r); if(mid>=l) ans += query(i<<1,l,r); return ans;}int main(void){ int t,case_t = 1; cin>>t; while(t--) { int n; scanf("%d",&n); for(int i=1;i<=n;i++) scanf("%d",&a[i]); build(1,1,n); char op[100]; printf("Case %d:/n",case_t++); while(~scanf("%s",op) && op[0]!='E') { int x,y; scanf("%d %d",&x,&y); if(op[0]=='Q') printf("%d/n",query(1,x,y)); else if(op[0]=='A') update(1,x,y); else update(1,x,-y); } } return 0;}新聞熱點
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