Vijos P1782 borrowing classrooms (prefixes and && differential sequences)

Topic Link: Borrowing Classroom

Test instructions: Give n days to the number of classrooms, m to borrow classroom list, in order to borrow classroom, ask which list is not satisfied and output

Analysis: Can be done with the line segment tree, will T, the constant is larger, choose to maintain the prefix and the difference sequence, two-point answer can be

1#include <cstdio>2#include <cstring>3#include <algorithm>4 using namespacestd;5 6 intans,n,m,r[1001000],d[1001000],s[1001000],t[1001000],pre[1001000];7 //inline int read () {int X=0;char ch=getchar (); ch>= ' 0 ' &&ch<= ' 9 ')) Ch=getchar (); while (ch>= ' 0 ' &&ch<= ' 9 ') {x=x*10+ch-' 0 '; Ch=getchar ();}; return x;}8 9 intCheckintx)Ten { One     intsum=0; Amemset (PRE,0,sizeof(pre)); -      for(intI=1; i<=x;i++) pre[s[i]]+=d[i],pre[t[i]+1]-=D[i]; -      for(intI=1; i<=n;i++) the     { -sum+=Pre[i]; -         if(Sum>r[i])return 0; -     }     +     return 1; - } +  A intMain () at { -scanf"%d%d",&n,&m); -ans=0; -      for(intI=1; i<=n;++i) scanf ("%d", r+i); -      for(intI=1; i<=m;++i) {scanf (" %d%d%d", d+i,s+i,t+i);} -     intL=1, r=m; in      while(l<R) -     { to         intMid= (l+r) >>1; +         if(check (mid) = =0) ans=mid,r=mid; -         ElseL=mid+1; the     } *     if(ANS) printf ("-1\n%d\n", ans); $     ElsePuts"0"); Panax Notoginseng}

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Vijos P1782 borrowing classrooms (prefixes and && differential sequences)