hdu1689(线段树成段更新)

来源：互联网发布：php implements 编辑：程序博客网时间：2024/06/08 05:22

两种操作：1、set区间[a,b]上数字为v；2、查询[ 1 , n ]上的sum

代码如下：

#include<iostream>#include<algorithm>#include<cstring>#include<stack>#include<queue>#include<set>#include<map>#include<stdio.h>#include<stdlib.h>#include<ctype.h>#include<time.h>#include<math.h>#define N 100005#define inf 0x7ffffff#define eps 1e-9#define pi acos(-1.0)#define P system("pause")using namespace std;int res;struct node{    int l,r,set;}tree[4*N];void build(int o,int l,int r)//初始化所有的数字为1{    tree[o].l = l;    tree[o].r = r;    tree[o].set = 1;    if(l == r)        return;    int m = (l+r)/2;    build(2*o , l , m);    build(2*o+1 , m+1 , r);}void pushdown(int o)//-1表示颜色是杂色，如果修改区域不一样，则先将其子区域置为父值，对子区域进行操作{    if(tree[o].set != -1)    {        tree[2*o].set = tree[2*o+1].set = tree[o].set;        tree[o].set = -1;    }}void update(int o,int x,int y,int v)//将区间[x,y]上的数字设置为v{    if(x <= tree[o].l && tree[o].r <= y)    {        tree[o].set = v;        return;    }    pushdown(o);    int m = (tree[o].l+tree[o].r)/2;    if(x <= m) update(2*o,x,y,v);    if(y > m) update(2*o+1,x,y,v);}void query(int o,int x,int y)//查询区间[x,y]上的sum{    if(tree[o].set != -1 && x <= tree[o].l && tree[o].r <= y)    {        res += tree[o].set*(tree[o].r-tree[o].l+1);        return;    }    int m = (tree[o].l + tree[o].r)/2;    if(x <= m)   query(2*o,x,y);    if(y > m)  query(2*o+1,x,y);}int main(){//freopen("input.txt","r",stdin);//freopen("output.txt","w",stdout);    int t, z = 1;    scanf("%d",&t);    while(t--)    {        int n,m;        scanf("%d%d",&n,&m);        build(1,1,n);        int i;        while(m--)        {            int x,y,z;            scanf("%d%d%d",&x,&y,&z);            update(1,x,y,z);        }        res = 0;        query(1,1,n);        printf("Case %d: The total value of the hook is %d.\n",z++,res);    }    return 0;}

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