poj 2777 Count Color

  时隔2天才搞定， 哎， 最近各种忙啊， 忙得晕头转向。

明显的线段树， 对于搞过状态压缩的， 一看到颜色为1~30， 于是马上想起了位运算， 这题需要成段更新， 不然绝对的超时， 其余的按照模板来就行了。

#include<cstdio>#include<cstring>#include<iostream>#define L(u) (u<<1)#define R(u) (u<<1|1)using namespace std;const int N = 100005;int color[32];struct Node {int l, r, color;bool flag;} node[N<<2];void ini(){    color[1] = 1;    for(int i=2; i<=30; ++i)    color[i] = color[i-1]<<1;}void pushUp(int u){    node[u].color = node[L(u)].color | node[R(u)].color;}void pushDown(int u){    node[u].flag = false;    node[L(u)].color = node[u].color;    node[L(u)].flag = true;    node[R(u)].color = node[u].color;    node[R(u)].flag = true;}void build(int u,int left,int right){    node[u].l = left, node[u].r = right;    node[u].color = 1;    node[u].flag = false;    if(node[u].l==node[u].r)    {        node[u].flag = true;        return;    }    int mid = (node[u].l+node[u].r)>>1;    build(L(u), left, mid);    build(R(u), mid+1, right);}void upDate(int u,int left,int right,int val){   if(left<=node[u].l&&node[u].r<=right)   {       node[u].flag = true;       node[u].color = val;       return;   }   if(node[u].color == val)   {       return;   }   if(node[u].flag)   {       pushDown(u);   }   int mid = (node[u].l+node[u].r)>>1;   if(right<=mid) upDate(L(u),left,right,val);   else if(left>mid) upDate(R(u),left,right,val);   else    {    upDate(L(u),left,mid,val);    upDate(R(u),mid+1,right,val);    }    pushUp(u);}void query(int u,int left,int &sum,int right){    if(node[u].flag)    {        sum |= node[u].color;        return;    }    if(left<=node[u].l&&node[u].r<=right)    {        sum |= node[u].color;        return;    }    int mid = (node[u].l+node[u].r)>>1;    if(right<=mid)    query(L(u),left,sum,right);    else if(left>mid)    {    query(R(u),left,sum,right);    }    else    {        query(L(u),left,sum,mid);        query(R(u),mid+1,sum,right);    }}int judge(int sum) {    int ans = 0;    while(sum){        if(sum % 2) ans ++;        sum = sum>>1;    }    return ans;}int main(void){   int l, t, o;   char str[2];   scanf("%d%d%d",&l,&t,&o);   ini();   build(1, 1, l);   while(o--)   {    scanf("%s",str);    if(str[0] == 'P')    {     int ans =0;     int a,b;     scanf("%d%d",&a,&b);     if(a < b)     query(1,a,ans,b);     else      query(1,b,ans,a);     printf("%d\n",judge(ans));    }    else    {        int a,b,c;        scanf("%d%d%d",&a,&b,&c);        if(a < b)        upDate(1,a,b,color[c]);        else        upDate(1,b,a,color[c]);    }   }   return 0;}