POJ 2155 Matrix Two-dimensional line segment Tree + tag permanent?

Test Instructions:Link Method:Two-dimensional segment tree + tag Persistence parsing:Test instructions is relatively clear, calculate the memory 4000^2 is also acceptable, so began to yy two-dimensional line segment tree? For the first-level X-segment tree, each node opens a whole tree of Y-segments. A two-dimensional array is implemented? But found a problem ah, this question how pushdown Ah, Mark can't pass to go ah. If you give X a mark, then how do you know the passage of y? So I learned something new? Tag persistence. The subject is a single point of query, it should be a permanent mark should be the corresponding interval directly or not to go down? What about the query? All you need to do is make sure that all the intervals passing through that point are different or up at the time of the query. Looks pretty simple, too? Is the application of the tag permanence the time when the mark cannot be hit? Looks like it. In addition, the problem has a pit, different groups of data between the line, for this also PE once. Code:

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#define Lson l,mid,rt<<1#define Rson mid+1,r,rt<<1|1#define N 1010using namespace STD;intT,n,q,ans;Chars[5];intsum[n<<2][n<<2];voidUpdate2 (intLintRintLintRintRtxintRty) {if(L&LT;=L&AMP;&AMP;R&LT;=R) {sum[rtx][rty]^=1;return; }intMid= (l+r) >>1;if(L>mid) Update2 (l,r,mid+1,r,rtx,rty<<1|1);Else if(R<=mid) Update2 (l,r,l,mid,rtx,rty<<1);Else{Update2 (l,mid,l,mid,rtx,rty<<1); Update2 (mid+1, r,mid+1,r,rtx,rty<<1|1); }}voidUpdateintX1,intX2,intY1,intY2,intLintRintRT) {if(X1&LT;=L&AMP;&AMP;R&LT;=X2) {Update2 (Y1,y2,1, N,rt,1);return; }intMid= (l+r) >>1;if(x1>mid) update (X1,x2,y1,y2,rson);Else if(x2<=mid) update (X1,x2,y1,y2,lson);Else{Update (X1,mid,y1,y2,lson); Update (mid+1, X2,y1,y2,rson); }}voidQuery2 (intY1,intLintRintRtxintRty) {Ans^=sum[rtx][rty];if(L==R) {return; }intMid= (l+r) >>1;if(Y1<=mid) Query2 (y1,l,mid,rtx,rty<<1);ElseQuery2 (y1,mid+1,r,rtx,rty<<1|1);}voidQueryintX1,intY1,intLintRintRT) {Query2 (y1,1, N,rt,1);if(L==R) {return; }intMid= (l+r) >>1;if(x1<=mid) query (x1,y1,l,mid,rt<<1);ElseQuery (x1,y1,mid+1,r,rt<<1|1);}intMain () {scanf("%d", &t); while(t--) {memset(Sum,0,sizeof(sum));scanf("%d%d", &n,&q); for(intI=1; i<=q;i++) {scanf('%s ', s);if(s[0]==' C ')            {intX1,y1,x2,y2;scanf("%d%d%d%d", &x1,&y1,&x2,&y2); Update (X1,x2,y1,y2,1N1); }Else{ans=0;intX1,y1;scanf("%d%d", &x1,&y1); Query (X1,y1,1N1);printf("%d\n", ans); }        }printf("\ n"); }}

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POJ 2155 Matrix Two-dimensional line segment Tree + tag permanent?