pku 1177 pictures (线段树+扫描线+离散化)

只能说与pku1151相似，别的还没有发言权

哎~~~~~~~~~~愿自己一路走好！！！！！

 

代码：

 

#include<iostream>#include<cstdlib>#include<cmath>#define N 5005using namespace std;struct elem{double x;double ly;double ry;bool flag;};struct node{int l;int r;int lc,rc;int line;int cover;double m;};elem cor[2*N];node tree[8*N];double index[2*N];int len;int n;double xres,yres;int cmp(const void *a,const void *b){if((*(elem *)a).x > (*(elem *)b).x)return 1;else if((*(elem *)a).x == (*(elem *)b).x)return 0;else return -1;}int cmp1(const void *a,const void *b){if(*(double *)a > *(double *)b)return 1;else if(*(double *)a == *(double *)b)return 0;else return -1;}void init(){int i;int k;double x1,y1,x2,y2;for(i = 0;i < n;i++){cin >>x1 >>y1 >>x2 >>y2;k = i<<1;cor[k].x = x1; cor[k].ly = y1; cor[k].ry = y2;cor[k].flag = true;cor[k+1].x = x2; cor[k+1].ly = y1; cor[k+1].ry = y2;cor[k+1].flag = false;index[k] = y1; index[k+1] = y2;}qsort(cor,2*n,sizeof(cor[0]),cmp);qsort(index,2*n,sizeof(index[0]),cmp1);len = 0;for(i = 1;i < 2*n;i++){if(index[i] != index[i-1])index[++len] = index[i];}//for(i = 0;i <= len;i++)//cout <<index[i] <<' ';//cout <<endl;return ;}int find(double x){int mid;int base = 0,top = len;while(base <= top){mid = (base+top)/2;if(x < index[mid])top = mid-1;else if(x > index[mid])base = mid+1;else return mid;}return -1;}void init_m(int k){int L,R;if(tree[k].cover > 0){tree[k].m = index[tree[k].r]-index[tree[k].l];return ;}L = k<<1; R = L+1;if(tree[k].r-tree[k].l > 1){tree[k].m = tree[L].m+tree[R].m;return ;}tree[k].m = 0;return ;}void init_line(int k){int L,R;if(tree[k].cover > 0){tree[k].line = 1;tree[k].lc = 1; tree[k].rc = 1;return ;}L = k<<1; R = L+1;if(tree[k].r-tree[k].l > 1){tree[k].lc = tree[L].lc; tree[k].rc = tree[R].rc;tree[k].line = tree[L].line+tree[R].line;if(tree[L].rc && tree[R].lc)tree[k].line--;return ;}tree[k].lc = tree[k].rc = 0;tree[k].line = 0;return ;}void buid_tree(int k,int left,int right){int mid;int L,R;tree[k].l = left; tree[k].r = right;tree[k].cover = 0;tree[k].m = 0; tree[k].line = 0;if(tree[k].r-tree[k].l == 1)return ;mid = (tree[k].l+tree[k].r)/2;L = k<<1; R = L+1;buid_tree(L,left,mid);buid_tree(R,mid,right);return ;}void tree_insert(int k,int left,int right){//if(k == 1) cout <<left <<' ' <<right <<endl;int mid;int L,R;if(left <= tree[k].l && right >= tree[k].r){tree[k].cover++;init_m(k); init_line(k);return ;}mid = (tree[k].l+tree[k].r)/2;L = k<<1; R = L+1;if(left < mid) tree_insert(L,left,right);if(right > mid) tree_insert(R,left,right);init_m(k);init_line(k);return ;}void tree_delete(int k,int left,int right){int mid;int L,R;if(left <= tree[k].l && right >= tree[k].r){tree[k].cover--;init_m(k);init_line(k);return ;}mid = (tree[k].l+tree[k].r)/2;L = k<<1; R = L+1;if(left < mid) tree_delete(L,left,right);if(right > mid) tree_delete(R,left,right);init_m(k);init_line(k);return ;}int main(){int i;double pre_m;while(cin >>n){xres = 0; yres = 0; pre_m = 0;init();buid_tree(1,0,len);for(i = 0;i < (2*n-1);i++){//cout <<cor[i].ly <<' ' <<cor[i].ry <<endl;if(cor[i].flag)tree_insert(1,find(cor[i].ly),find(cor[i].ry));elsetree_delete(1,find(cor[i].ly),find(cor[i].ry));xres += tree[1].line*(cor[i+1].x-cor[i].x)*2;yres += fabs(tree[1].m-pre_m);pre_m = tree[1].m;}tree_delete(1,find(cor[i].ly),find(cor[i].ry));yres += fabs(tree[1].m-pre_m);printf("%.0lf/n",yres+xres);}return 0;}