标签：style blog color os io for 代码 div
这个题目就是考察线段树的基本用法，我自己打了代码，其实就是照模板来的，大概思想已经弄懂了。用c++不能过，说我超时，就改成c的读入读出，这坑爹的过了。我最爱的c++，你肿么了。。。
这是ac的代码：
#include<iostream> #include<cstring> #include<cstdio> using namespace std; int n,m; int num[100005]; struct H { int l,r,sum; }trees[300005]; void build_trees(int jd,int l,int r) { trees[jd].l=l; trees[jd].r=r; if(l==r) {trees[jd].sum=num[l];return ;} int mid = (l+r)/2; build_trees(jd*2,l,mid); build_trees(jd*2+1,mid+1,r); trees[jd].sum=trees[jd*2].sum+trees[jd*2+1].sum; } void update(int jd,int a,int b) { if(trees[jd].l==trees[jd].r) trees[jd].sum+=b; else { int mid = (trees[jd].l+trees[jd].r)/2; if(a<=mid) update(jd*2,a,b); else update(jd*2+1,a,b); trees[jd].sum=trees[jd*2].sum+trees[jd*2+1].sum; } } int query(int jd , int l,int r) { if(l<=trees[jd].l&&r>=trees[jd].r) return trees[jd].sum; int ans=0; int mid = (trees[jd].l+trees[jd].r)/2; if(l<=mid) ans+=query(jd*2,l,r); if(r>mid) ans+=query(jd*2+1,l,r); return ans; } int main() { int t; int i,j,cas; int a,b; char st[10]; scanf("%d",&t); for(cas=1;cas<=t;cas++) { memset(num,0,sizeof num); scanf("%d",&n); for(i=1;i<=n;i++) { scanf("%d",&num[i]); } build_trees(1,1,n); printf("Case %d:\n",cas); for(;;) { scanf("%s",st); if(st[0]==‘E‘) break; scanf("%d%d",&a,&b); if(st[0]==‘A‘) update(1,a,b); if(st[0]==‘S‘) update(1,a,-b); if(st[0]==‘Q‘) printf("%d\n",query(1,a,b)); } } return 0; }
这是没ac的代码：
#include<iostream> #include<cstring> #include<cstdio> using namespace std; int n,m; int num[100005] = {0}; struct H { int l,r,sum; }trees[300005]; void build_trees(int jd,int l,int r) { trees[jd].l=l; trees[jd].r=r; if(l==r) {trees[jd].sum=num[l];return ;} int mid = (l+r)/2; build_trees(jd*2,l,mid); build_trees(jd*2+1,mid+1,r); trees[jd].sum=trees[jd*2].sum+trees[jd*2+1].sum; } void update(int jd,int a,int b) { if(trees[jd].l==trees[jd].r) trees[jd].sum+=b; else { int mid = (trees[jd].l+trees[jd].r)/2; if(a<=mid) update(jd*2,a,b); else update(jd*2+1,a,b); trees[jd].sum=trees[jd*2].sum+trees[jd*2+1].sum; } } int query(int jd , int l,int r) { if(l<=trees[jd].l&&r>=trees[jd].r) return trees[jd].sum; int ans=0; int mid = (trees[jd].l+trees[jd].r)/2; if(l<=mid) ans+=query(jd*2,l,r); if(r>mid) ans+=query(jd*2+1,l,r); return ans; } int main() { int l,r; cin >> m; char s[10]; for(int j = 1;j <= m;j++) { cin >> n; for(int i = 1;i <= n;i++) { cin >> num[i]; } build_trees(1,1,n); cout << "Case " << j << endl; while(1) { cin >> s; if(s[0] == ‘E‘) { break; } else if(s[0] == ‘Q‘) { cin >> l >> r; int ans = query(1,l,r); cout << ans << endl; } else if(s[0] == ‘A‘) { cin >> l >> r; update(1,l,r); } else if(s[0] == ‘S‘) { cin >> l>> r; update(1,l,-r); } } } return 0; }
标签：style blog color os io for 代码 div
原文地址：http://www.cnblogs.com/hhhhhhhhhhhhhhhhhhhhhhhhhhh/p/3875338.html
