源代码

     1	#include<bits/stdc++.h>
     2	using namespace std;
     3	
     4	const long long MAXN=100;
     5	
     6	long long n,q;
     7	struct Line{
     8		long long k,b;
     9		double operator+(const Line& other)const{
    10			return 1.0*(other.b-b)/(k-other.k);
    11		}
    12	}lines[MAXN];
    13	struct Query{
    14		long long x,id;
    15	}queries[MAXN];
    16	long long front=0,rear=0,que[MAXN];
    17	long long ans[MAXN]={0};
    18	
    19	bool cmp(Line a,Line b){
    20		return a.k>b.k;
    21	}
    22	
    23	bool cmp2(Query a,Query b){
    24		return a.x<b.x;
    25	}
    26	
    27	int main(){
    28		long long i,j;
    29		cin>>n>>q;
    30		for(i=0;i<n;i++)
    31			cin>>lines[i].k>>lines[i].b;
    32		for(i=0;i<q;i++){
    33			cin>>queries[i].x;
    34			queries[i].id=i;
    35		}
    36		sort(lines,lines+n,cmp);
    37		sort(queries,queries+q,cmp2);
    38		for(i=0;i<n;i++){
    39			while(rear-front>1 && lines[que[rear-1]]+lines[que[rear-2]]>lines[i]+lines[que[rear-1]])
    40				rear--;
    41			que[rear++]=i;
    42		}
    43		for(i=0;i<q;i++)
    44			while(rear-front>1 && lines[que[front]]+lines[que[front+1]]<queries[i].x)
    45				front++;
    46			ans[queries[i].id]=lines[que[front]].k*queries[i].x+lines[que[front]].b;
    47		}
    48		for(i=0;i<n;i++)
    49			cout<<ans[i]<<' ';
    50		cout<<endl;
    51		return 0;
    52	}

编译信息

10-convexhullopt.cpp:48:2: error: expected unqualified-id before ‘for’
  for(i=0;i<n;i++)
  ^~~
10-convexhullopt.cpp:48:10: error: ‘i’ does not name a type
  for(i=0;i<n;i++)
          ^
10-convexhullopt.cpp:48:14: error: ‘i’ does not name a type
  for(i=0;i<n;i++)
              ^
10-convexhullopt.cpp:50:2: error: ‘cout’ does not name a type; did you mean ‘cosl’?
  cout<<endl;
  ^~~~
  cosl
10-convexhullopt.cpp:51:2: error: expected unqualified-id before ‘return’
  return 0;
  ^~~~~~
10-convexhullopt.cpp:52:1: error: expected declaration before ‘}’ token
 }
 ^
[taocp@doorofacp Basic]$ g++ -o 10-convexhullopt 10-convexhullopt.cpp 
10-convexhullopt.cpp:48:2: error: expected unqualified-id before ‘for’
  for(i=0;i<n;i++)
  ^~~
10-convexhullopt.cpp:48:10: error: ‘i’ does not name a type
  for(i=0;i<n;i++)
          ^
10-convexhullopt.cpp:48:14: error: ‘i’ does not name a type
  for(i=0;i<n;i++)
              ^
10-convexhullopt.cpp:50:2: error: ‘cout’ does not name a type; did you mean ‘cosl’?
  cout<<endl;
  ^~~~
  cosl
10-convexhullopt.cpp:51:2: error: expected unqualified-id before ‘return’
  return 0;
  ^~~~~~
10-convexhullopt.cpp:52:1: error: expected declaration before ‘}’ token
 }
 ^

不知道为什么for循环CE