HDU 1540 (interval merger)

#include <stdio.h>#include<stdlib.h>#include<string.h>#defineMAXN 50010#defineLson root*2#defineRson root*2+1#defineMax (A, B) (A&GT;B?A:B)intAC[MAXN];structndoe{//The lsum represents the continuity of the left interval, the rsum represents the continuous in the right interval, and sum indicates the continuity of the intermediate interval;    intL,r; intlsum,rsum,sum; intMid () {return(r+l)/2; }    intLen () {return(r-l+1); }} A[MAXN*4];voidBuildtree (intRootintLintR) {A[root]. L=l,a[root]. R=R; A[root].lsum= A[root].rsum = A[root].sum =A[root].len (); if(L==R)return ; Buildtree (Lson,l,a[root].    Mid ()); Buildtree (Rson,a[root]. Mid ()+1, R);}voidPushup (introot) {A[root].lsum= a[lson].lsum, a[root].rsum = a[rson].rsum;//The maximum continuous of the left interval is the maximal continuity of the child nodes, and the right interval is the same;    if(A[lson].lsum = = A[lson].len ())//if the maximum continuous of a child node equals its length, then its maximum continuous can be added to the left continuous of the right interval;A[root].lsum = A[lson].lsum +a[rson].lsum; if(A[rson].rsum = =A[rson].len ()) A[root].rsum= A[rson].rsum +a[lson].rsum; A[root].sum= Max (A[root].lsum, Max (A[root].rsum, a[lson].rsum+a[rson].lsum));//The maximum value of the middle interval is three number (left continuous, right continuous, left continuous of right continuous + right interval of child node left interval)}voidUpdateintRootintKinte) {    if(A[root]. L = =A[root]. R) {a[root].lsum= A[root].rsum = A[root].sum =e; return ; }    if(k <=A[root].    Mid ()) Update (Lson, K, E); ElseUpdate (Rson, K, E); Pushup (root);}intQuery (intRootintk) {    if(A[root].sum = =0 )        return 0; if(K < A[root]. L +a[root].lsum)//determine whether it is in the left interval, K < left endpoint + left continuous;        returna[root].lsum; if(k > A[root]. R-a[root].rsum)//determine if it is in the right interval; k > Right end point-right continuous;        returna[root].rsum; if(k > (A[lson]. R-a[lson].rsum) && K < (A[rson]. L + a[rson].lsum))//Judging whether in the middle; Right endpoint-right continuous < K < Left end + left continuous;        returnA[rson].lsum +a[lson].rsum; if(k<=A[root]. Mid ())returnQuery (lson,k); Else        returnQuery (rson,k);}intMain () {intn,m,k,w; Charstr[Ten];  while(~SCANF ("%d%d",&n,&m)) {k=0; Buildtree (1,1, N);  while(m--) {scanf ("%s", str); if(str[0]=='D') {scanf ("%d",&W); AC[K]=W; Update (1W0); K++; }            if(str[0]=='R') {k--; W=Ac[k]; Update (1W1); }            if(str[0] =='Q') {scanf ("%d",&W); printf ("%d\n", Query (1, W)); }        }    }    return 0;}

HDU 1540 (interval merger)