//9379418 NKHelloWorld 1389 Accepted 296K 16MS C++ 1997B 2011-10-01 12:31:16 //9379419 NKHelloWorld 1389 Accepted 844K 0MS G++ 1997B 2011-10-01 12:31:31 /* POJ1151的整数简化版本,套用模板1A */ #include <algorithm> #include <iostream> #include <cstdio> using namespace std; #define L(x) ( x << 1 ) #define R(x) ( x << 1 | 1 ) int y[3000]; struct Line { int x, y1, y2,flag; } line[3000]; struct Node { int l, r, cover; int lf, rf, len; } node[10000]; bool cmp ( Line a, Line b ) { return a.x < b.x; } void length ( int u ) { if ( node[u].cover > 0 ) { node[u].len = node[u].rf - node[u].lf; return; } else if ( node[u].l + 1 == node[u].r ) node[u].len = 0; /* 叶子节点,len 为 0 */ else node[u].len = node[L(u)].len + node[R(u)].len; } void build ( int u, int l, int r ) { node[u].l = l; node[u].r = r; node[u].lf = y[l]; node[u].rf = y[r]; node[u].len = node[u].cover = 0; if ( l + 1 == r ) return; int mid = ( l + r ) / 2; build ( L(u), l, mid ); build ( R(u), mid, r ); } void update ( int u, Line e ) { if ( e.y1 == node[u].lf && e.y2 == node[u].rf ) { node[u].cover += e.flag; length ( u ); return; } if ( e.y1 >= node[R(u)].lf ) update ( R(u), e ); else if ( e.y2 <= node[L(u)].rf ) update ( L(u), e ); else { Line temp = e; temp.y2 = node[L(u)].rf; update ( L(u), temp ); temp = e; temp.y1 = node[R(u)].lf; update ( R(u), temp ); } length ( u ); } int main() { int n, t,i; int x1,y1,x2,y2,ans; while(1) { t = n = 1; while(scanf("%d%d%d%d",&x1,&y1,&x2,&y2),x1!=-1) { line[t].x = x1; line[t].y1 = y1; line[t].y2 = y2; line[t].flag = 1; y[t] = y1; t++; line[t].x = x2; line[t].y1 = y1; line[t].y2 = y2; line[t].flag = -1; y[t] = y2; t++; n++; } if(n==1) break; n--; sort ( line + 1, line + t, cmp ); sort ( y + 1, y + t ); build ( 1, 1, t-1 ); update ( 1, line[1] ); ans = 0; for ( i = 2; i < t; i++ ) { ans += node[1].len * ( line[i].x - line[i-1].x ); update ( 1, line[i] ); } printf("%d\n",ans); } return 0; }