ACM_线段树模板（区间更新）

first code(求总和):

#include 
#include 
using namespace std;
#define lchild left, mid, root<<1
#define rchild mid+1, right, root<<1|1
#define maxn 100100
int lazy[maxn<<2];
int sum[maxn<<2];

void update(int root)
{
    sum[root] = sum[root<<1]+sum[root<<1|1];
}

void lazyup(int root, int sub)
{
    if (lazy[root])
    {
        lazy[root<<1] = lazy[root<<1|1] = lazy[root];
        sum[root<<1] = (sub-sub/2)*lazy[root];
        sum[root<<1|1] = (sub/2)*lazy[root];
        lazy[root] = 0;
    }
}

void build(int left, int right, int root)
{
    lazy[root] = 0;
    sum[root] = 1;
    if (left==right)
        return;
    int mid  = (left+right)>>1;
    build(lchild);
    build(rchild);
    update(root);
}

void operate(int l, int r, int c, int left, int right, int root)
{
    if (l<=left&&r>=right)
    {
        lazy[root] = c;
        sum[root] = c*(right-left+1);
        return;
    }
    lazyup(root, right-left+1);
    int mid = (left+right)>>1;
    if (l<=mid)
        operate(l,r,c,lchild);
    if (r>mid)
        operate(l,r,c,rchild);
    update(root);

}
int main()
{
    int N,n,m;
    cin>>N;
    int t=N;
    while (N--)
    {
        scanf("%d%d",&n,&m);
        build (1,n,1);
        while (m--)
        {
            int a,b,c;
            scanf("%d%d%d",&a,&b,&c);
            operate(a,b,c,1,n,1);

        }
        printf("Case %d: The total value of the hook is %d.\n", t-N, sum[1]);
    }
    return 0;
}

second code（求每个） :

#include 
#include 
using namespace std;

int ans[1000000],n;
struct node
{
    int l,r,n;
}a[1000000];
void build(int left, int right ,int root)
{
    a[root].l = left;
    a[root].r = right;
    a[root].n = 0;
    if (left!=right)
    {
        int mid = (left+right)>>1;
        build(left, mid, root<<1);
        build(mid+1, right, root<<1|1);
    }
}

void operate(int left, int right, int root)
{
    if (a[root].l==left&&a[root].r==right)
    {
        a[root].n++;
    }
    else
    {
        int mid  = (a[root].l+a[root].r)>>1;
        if (right<=mid)
        {
            operate(left,right,root<<1);
        }
        else if(left>mid)
        {
            operate(left,right,root<<1|1);
        }
        else
        {
            operate(left,mid,root<<1);
            operate(mid+1,right,root<<1|1);

        }
    }
}

void add(int root)
{
    int i;
    for(i = a[root].l; i<=a[root].r; i++)//该区间所有编号都被刷了一次
        ans[i]+=a[root].n;
    if(a[root].l == a[root].r)
        return;
    add(root<<1);
    add(root<<1|1);
}
int main()
{
    int n,i,j;
    while (scanf("%d",&n),n!=0)
    {
        build(1,n,1);
        int x,y;
        for(int i = 1; i<=n; i++)
        {
            scanf("%d%d",&x,&y);
            operate(x,y,1);
        }
        memset(ans,0,sizeof(ans));
        add(1);
        printf("%d",ans[1]);
        for(i = 2; i<=n; i++)
            printf(" %d",ans[i]);
        printf("\n");
    }
    return 0;
}