HDU 1166 敌兵布阵
(更新点查询区间)
好吧，今天算是被这道题坑惨了，TLE了许久，结果发现原来就是用了一个cout的原因。。改成printf后一下就过了，而且时间一下缩短数倍。。俗话说，吃一堑，长一智，，我算是长记性了。。
代码：
#include <iostream> #include <cstdio> #include <cstring> #include <cmath> #include <algorithm> #include <cstdlib> using namespace std; #define N 50011 int tree[4*N]; int a[N]; void build(int l,int r,int rt) { if(l==r) { scanf("%d",&tree[rt]); return; } int mid = (l+r)/2; build(l,mid,2*rt); build(mid+1,r,2*rt+1); tree[rt] = tree[2*rt] + tree[2*rt+1]; } void update(int l,int r,int pos,int val,int rt) { if(l==r) { tree[rt] += val; return; } int mid = (l+r)/2; if(pos<=mid) update(l,mid,pos,val,2*rt); else update(mid+1,r,pos,val,2*rt+1); tree[rt] = tree[2*rt] + tree[2*rt+1]; } int query(int l,int r,int aa,int bb,int rt) { if(aa>r||bb<l) return 0; if(aa<=l&&bb>=r) return tree[rt]; int mid = (l+r)/2; if(bb<=mid) return query(l,mid,aa,bb,2*rt); else if(aa>mid) return query(mid+1,r,aa,bb,2*rt+1); return query(l,mid,aa,bb,2*rt)+query(mid+1,r,aa,bb,2*rt+1); } int main() { int t,n,i; char ss[10]; int aa,bb; scanf("%d",&t); int cs = 1; while(t--) { memset(tree,0,sizeof(tree)); scanf("%d",&n); build(1,n,1); printf("Case %d:\n",cs++); while(scanf("%s",ss)&&ss[0]!='E') { scanf("%d%d",&aa,&bb); if(ss[0] == 'A') update(1,n,aa,bb,1); else if(ss[0] == 'S') update(1,n,aa,-bb,1); else if(ss[0] == 'Q') { int ans = query(1,n,aa,bb,1); printf("%d\n",ans); //Don't use cout! } } } return 0; }