洛谷P4643 [国家集训队]阿狸和桃子的游戏 & 初赛心情 洛谷P4643 [国家集训队]阿狸和桃子的游戏

 1 #include<iostream>
 2 #include<algorithm>
 3 #include<cstdio>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<map>
 7 #include<set>
 8 #include<queue>
 9 #include<vector>
10 #define IL inline
11 #define re register
12 #define LL long long
13 #define ULL unsigned long long
14 #define re register
15 using namespace std;
16 
17 template<class T>inline void read(T&x)
18 
19 {
20     char ch=getchar();
21     while(!isdigit(ch))ch=getchar();
22     x=ch-'0';ch=getchar();
23     while(isdigit(ch)){x=x*10+ch-'0';ch=getchar();}
24 }
25 inline int read()
26 {
27     int x=0;
28     char ch=getchar();
29     while(!isdigit(ch))ch=getchar();
30     x=ch-'0';ch=getchar();
31     while(isdigit(ch)){x=x*10+ch-'0';ch=getchar();}
32     return x;
33 }
34 int G[55];
35 template<class T>inline void write(T x)
36 {
37     int g=0;
38     do{G[++g]=x%10;x/=10;}while(x);
39     for(re int i=g;i>=1;--i)putchar('0'+G[i]);putchar('
');
40 }
41 int n,m;
42 double ans,a[10010];
43 bool cmp(const double & a,const double & b){
44     return a>b;
45 }
46 int main()
47 {
48     cin>>n>>m;
49     for(int i=1;i<=n;i++) cin>>a[i];
50     for(int i=1,x,y;i<=m;i++)
51     {
52         double z;
53         cin>>x>>y>>z;
54         a[x]+=z/2;
55         a[y]+=z/2;
56     }
57     sort(a+1,a+n+1,cmp);
58     for(int i=1;i<=n;i++) if(i&1) ans+=a[i];else ans-=a[i];
59     cout<<ans;
60     return 0;
61 }