nyoj1068 ST 线段树

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题目链接
线段树查询区间和以及区间奇数个数。
区间和很好求，很快就写好了，区间奇数个数写起来麻烦一点，除了查询的时候需要lazy操作，更新的时候也需要lazy操作。
直接上代码：

#include<stdio.h>#include<string.h>#define ll long long#define maxn 10010struct stu{    ll l,r,mid,lazysum,odd,sum,lazyodd;  } w[maxn<<2];void build(ll l,ll r,ll tr)   //建树{    w[tr].mid=(l+r)>>1;    w[tr].l=l,w[tr].r=r,w[tr].odd=0,w[tr].lazysum=0,w[tr].lazyodd=0;    if(l==r)        scanf("%lld",&w[tr].sum),w[tr].odd=w[tr].sum&1;    else    {        build(l,w[tr].mid,tr<<1),build(w[tr].mid+1,r,tr<<1|1);        w[tr].sum=w[tr<<1].sum+w[tr<<1|1].sum;        w[tr].odd=w[tr<<1].odd+w[tr<<1|1].odd;    }}void update(ll x,ll y,ll z,ll tr)  //更新{    if(w[tr].lazyodd&&w[tr].l!=w[tr].r)  //若有lazyodd，且不是叶子节点    {        w[tr<<1].lazyodd^=1,w[tr<<1|1].lazyodd^=1;  //子节点的lazyodd若为0，就变成1，若为1，就变成0        w[tr<<1].odd=w[tr<<1].r-w[tr<<1].l+1-w[tr<<1].odd;//无论子节点的lazyodd是否为1，均更新子节点的odd个数        w[tr<<1|1].odd=w[tr<<1|1].r-w[tr<<1|1].l+1-w[tr<<1|1].odd;        w[tr].lazyodd=0;   //向子节点传递lazyodd后，清零    }    if(w[tr].l==x&&w[tr].r==y)    {        w[tr].lazysum+=z;  //更新lazysum        w[tr].sum+=(y-x+1)*z;           if(z&1)            w[tr].lazyodd^=1,w[tr].odd=w[tr].r-w[tr].l+1-w[tr].odd;  //若要加的数为奇数，无论lazyodd是否为奇数，均更新tr区间奇数个数        return ;    }    else if(y<=w[tr].mid)        update(x,y,z,tr<<1);    else if(x>w[tr].mid)        update(x,y,z,tr<<1|1);    else        update(x,w[tr].mid,z,tr<<1),update(w[tr].mid+1,y,z,tr<<1|1);    w[tr].sum+=(y-x+1)*z;   //更新sum    if(z&1)        w[tr].odd=w[tr<<1].odd+w[tr<<1|1].odd;  //更新线段树中包含(x,y)区间的区间奇数个数}ll query_odd(ll x,ll y,ll tr){    if(w[tr].lazyodd&&w[tr].l!=w[tr].r)  //和update类似    {        w[tr<<1].lazyodd^=1,w[tr<<1|1].lazyodd^=1;        w[tr<<1].odd=w[tr<<1].r-w[tr<<1].l+1-w[tr<<1].odd;        w[tr<<1|1].odd=w[tr<<1|1].r-w[tr<<1|1].l+1-w[tr<<1|1].odd;        w[tr].lazyodd=0;    }    if(w[tr].l==x&&w[tr].r==y)        return w[tr].odd;    else if(w[tr].mid>=y)        return query_odd(x,y,tr<<1);    else if(w[tr].mid<x)        return query_odd(x,y,tr<<1|1);    else        return query_odd(x,w[tr].mid,tr<<1)+query_odd(w[tr].mid+1,y,tr<<1|1);}ll query_sum(ll x,ll y,ll tr){    if(w[tr].lazysum&&w[tr].l!=w[tr].r)  //sum的lazy操作    {        w[tr<<1].lazysum+=w[tr].lazysum;        w[tr<<1|1].lazysum+=w[tr].lazysum;        w[tr<<1].sum+=(w[tr<<1].r-w[tr<<1].l+1)*w[tr].lazysum;        w[tr<<1|1].sum+=(w[tr<<1|1].r-w[tr<<1|1].l+1)*w[tr].lazysum;        w[tr].lazysum=0;    }    if(w[tr].l==x&&w[tr].r==y)        return w[tr].sum;    else if(y<=w[tr].mid)        return query_sum(x,y,tr<<1);    else if(x>w[tr].mid)        return query_sum(x,y,tr<<1|1);    else        return query_sum(x,w[tr].mid,tr<<1)+query_sum(w[tr].mid+1,y,tr<<1|1);}int main(){    ll n,m,i,j,x,z,y;    while(scanf("%lld%lld",&n,&m)!=EOF)    {        char c;        build(1,n,1);        while(m--)        {            scanf("\n%c",&c);            scanf("%lld%lld",&x,&y);            if(c=='S')                printf("%lld\n",query_sum(x,y,1));            else if(c=='Q')                printf("%lld\n",query_odd(x,y,1));            else            {                scanf("%lld",&z);                update(x,y,z,1);            }        }    }    return 0;}

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