POJ 2777 Count Color 線段樹

 題意：對長木板進行塗色，有兩種操作, 一種插入，一種統計，輸出一定範圍內的顏色種數。

#include<cstdio>#include<algorithm>#include<cstring>using namespace std;#define L(u) (u<<1)#define R(u) (u<<1|1)#define N 150000struct TreeNode { int l,r,c;};TreeNode node[N*3];int kind, mark[31];void build ( int u, int l, int r ){    node[u].l = l;    node[u].r = r;    node[u].c = 1;if ( l == r ) return;int mid = ( l + r ) >> 1;build ( L(u), l, mid );build ( R(u), mid + 1, r );}void update ( int u, int l, int r, int c ){    if ( node[u].c == c ) return;if ( node[u].l == l && node[u].r == r ){node[u].c = c; return;}if ( node[u].c != -1 ){    node[L(u)].c = node[R(u)].c = node[u].c;node[u].c = -1;    }int mid = (node[u].l + node[u].r) >> 1;if ( r <= mid ) update (L(u),l,r,c);else if ( l > mid ) update (R(u),l,r,c);else update (L(u),l,mid,c), update(R(u),mid+1,r,c);}void query ( int u, int l, int r ){if ( node[u].c != -1 )    {if( !mark[node[u].c] )        {            mark[node[u].c] = 1;            kind++;        }return;}int mid = (node[u].l + node[u].r) >> 1;if ( r <= mid ) query (L(u),l,r);else if ( l > mid ) query (R(u),l,r);else query(L(u),l,mid), query(R(u),mid+1,r);}int main(){int L, T, O, a, b, c;char oper[10];scanf("%d%d%d", &L, &T, &O);build ( 1, 1, L );while ( O-- ){scanf("%s %d %d",oper, &a, &b);if ( a > b ) swap(a,b);if ( oper[0] == 'P' ){kind = 0;memset(mark,0,sizeof(mark));query ( 1, a, b );printf("%d\n", kind );}else{scanf("%d",&c);update ( 1, a, b, c );}}return 0;}