hdu1166 敌兵布阵 线段树 单点更新

http://acm.hdu.edu.cn/showproblem.php?pid=1166

入门级单点更新线段树，sum维护区间总的人数

#include <set>#include <map>#include <queue>#include <stack>#include <deque>#include <math.h>#include <string>#include <vector>#include <stdio.h>#include <iostream>#include <string.h>#include <algorithm>#include <functional>#define mem(a) memset(a,0,sizeof(a));#define mem_1(a) memset(a,-1,sizeof(a));#define sf(a) scanf("%d",&a)#define sff(a,b) scanf("%d%d",&a,&b)#define sfff(a,b,c) scanf("%d%d%d",&a,&b,&c)#define LL long long#define lson l, mid, root<<1#define rson mid+1, r, root<<1|1const int INF = 0x7FFFFFFF;const int MAXN = 50000;const double PI = acos(-1.0);const double esp = 1e-10;using namespace std;struct node{    int l,r,sum;}Tree[MAXN<<2];void build_tree(int l, int r, int root){    Tree[root].l = l;    Tree[root].r = r;    if(l == r)    {        scanf("%d",&Tree[root].sum);       // cout << Tree[root].l << Tree[root].r << endl;        return ;    }    int mid = (l + r) >> 1;    build_tree(l,mid,root<<1);    build_tree(mid+1,r,root<<1|1);    Tree[root].sum = Tree[root << 1].sum + Tree[root << 1|1].sum;}void updata(int l,int r,int root,int k){    if(l == Tree[root].l && r == Tree[root].r)    {        Tree[root].sum += k;        return ;    }    int mid = (Tree[root].l + Tree[root].r) >> 1;    if(r <= mid) updata(l,r,root<<1,k);    else if(mid < l) updata(l,r,root<<1|1,k);    else    {        updata(l,mid,root << 1,k);        updata(mid+1,r,root << 1|1 , k);    }    Tree[root].sum = Tree[root << 1].sum + Tree[root << 1|1].sum;}int Query(int l,int r,int root){    if(l == Tree[root].l && r == Tree[root].r)        return Tree[root].sum;    int mid = (Tree[root].l + Tree[root].r) >> 1;    int ans = 0;    if(r <= mid) ans += Query(l,r,root<<1);    else if(mid < l) ans+=Query(l,r,root<<1|1);    else        ans+=Query(l,mid,root<<1) + Query(mid+1,r,root<<1|1);    return ans;}int main(){    int T,l,r,n,times=1;    char c[10];    sf(T);    while(T--)    {        sf(n);        build_tree(1,n,1);        printf("Case %d:\n", times++);        while(cin >> c)        {            if(strcmp(c,"Query")==0)            {                sff(l,r);                printf("%d\n",Query(l,r,1));            }            else if(strcmp(c,"Add")==0)            {                sff(l,r);                updata(l,l,1,r);            }            else if(strcmp(c,"Sub")==0)            {                sff(l,r);                updata(l,l,1,-r);            }            else                break;        }    }}