hdu 1556(树状数组)
摘要:题意:易知。。。思路:要求对树状数组的理解。代码实现:#include<iostream>#include<cmath>using namespace std;int n,a[100001];int lowbit(int x){ return x&(-x);}void build(int x,int y)//建树{ while(x<=n) { a[x]+=y; x+=lowbit(x); }}int sum(int x)//求和{ int s=0; while(x>0) { s=s+a[x]; x...
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posted @ 2013-03-09 15:34
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