POJ 3667 Hotel Segment Tree

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This topic needs to maintain three variables, one is the maximum continuous length of the interval, one is the longest prefix, and one is the longest suffix. Need to pay attention to is the query, first check whether the left interval is satisfied, and then should check the left and right interval junction whether meet, here to see pre_max[rt<<1|1]+suf_max[rt<<1|1] is greater than equal to the length of the given, The last is the right interval.

#include <iostream>#include<vector>#include<cstdio>#include<cstring>#include<algorithm>#include<cmath>#include<map>#include<Set>#include<string>#include<queue>using namespacestd;#definePB (x) push_back (x)#definell Long Long#defineMK (x, y) make_pair (x, y)#defineLson L, M, rt<<1#defineMem (a) memset (a, 0, sizeof (a))#defineRson m+1, R, rt<<1|1#defineMem1 (a) memset (a,-1, sizeof (a))#defineMEM2 (a) memset (a, 0x3f, sizeof (a))#defineRep (I, A, n) for (int i = A; i<n; i++)#defineull unsigned long Longtypedef pair<int,int>PLL;Const DoublePI = ACOs (-1.0);Const DoubleEPS = 1e-8;Const intMoD = 1e9+7;Const intINF =1061109567;Const intdir[][2] = { {-1,0}, {1,0}, {0, -1}, {0,1} };Const intMAXN =50005;intmaxx[maxn<<2], pre_max[maxn<<2], suf_max[maxn<<2], cover[maxn<<2];voidPushup (intRtintm) {Maxx[rt]= Max (maxx[rt<<1], maxx[rt<<1|1]); PRE_MAX[RT]= pre_max[rt<<1]; SUF_MAX[RT]= suf_max[rt<<1|1]; if(maxx[rt<<1] = = (M (m>>1)) ) Pre_max[rt]= pre_max[rt<<1] + pre_max[rt<<1|1]; if(maxx[rt<<1|1] = = (m>>1)) Suf_max[rt]= suf_max[rt<<1|1]+suf_max[rt<<1]; MAXX[RT]= Max (Maxx[rt], suf_max[rt<<1]+pre_max[rt<<1|1]);}voidBuildintLintRintRT) {Maxx[rt]= Pre_max[rt] = Suf_max[rt] = r-l+1; COVER[RT]= -1; if(L = =R)return ; intm = l+r>>1;    Build (Lson); Build (Rson);}voidPushdown (intRtintm) {if(~Cover[rt]) {Cover[rt<<1] = cover[rt<<1|1] =Cover[rt]; Maxx[rt<<1] = pre_max[rt<<1] = suf_max[rt<<1] = cover[rt]* (M-(m>>1)); Pre_max[rt<<1|1] = suf_max[rt<<1|1] = maxx[rt<<1|1] = cover[rt]* (m>>1); COVER[RT]= -1; }}voidUpdateintLintRintLintRintRtintval) {    if(l<=l&&r>=R) {Cover[rt]=Val; MAXX[RT]= Suf_max[rt] = Pre_max[rt] = val* (r-l+1); return ; } pushdown (RT, R-l+1); intm = l+r>>1; if(l<=m) Update (L, R, Lson, Val); if(r>m) Update (L, R, Rson, Val); Pushup (RT, R-l+1);}intQueryintValintLintRintRT) {    if(L = =R)returnl; Pushdown (RT, R-l+1); intm = l+r>>1; if(maxx[rt<<1]>=val)returnquery (Val, Lson); if(pre_max[rt<<1|1]+suf_max[rt<<1]>=val)returnm-suf_max[rt<<1]+1; returnquery (Val, Rson);}intMain () {intN, m, sign, x, y;  while(cin>>n>>m) {Build (1N1);  while(m--) {scanf ("%d", &Sign ); if(Sign = =1) {scanf ("%d", &x); if(maxx[1]<x) {cout<<0<<Endl; } Else {                    intpos = query (x,1N1); cout<<pos<<Endl; Update (POS, POS+x-1,1N1,0); }            } Else{scanf ("%d%d", &x, &y); Update (x, y+x-1,1N1,1); }        }    }}

POJ 3667 Hotel Segment Tree