Bzoj3399: [usaco 2009 Mar] sand castle

3399: [usaco 2009 Mar] sand castle time limit: 3 sec memory limit: 128 MB
Submit: 22 solved: 17
[Submit] [Status] Description John built a castle with sand. like all the walls of the castle, there are also many gunshots in the city wall. The part between the two adjacent gunshots is called the City tooth ". there are N (1 ≤ n ≤ 25000) City teeth on the city wall, each with a height mi. (1 ≤ limit ≤ 100000 ). now John wants to adjust the height of the city tooth to Bi, B2,... in some order ,..., BN (I ≤ Bi ≤100000 ). -John needs X (I ≤ x ≤ 100) for every increase of the height of a unit. John needs y (1 ≤ y ≤ 100) for every reduction of the height of a unit) RMB. ask John how much money he can use at least to achieve his goal. the data guarantee answer cannot exceed 2 ^ 32. input 3 integers n, x, y in the row 1st. from 2nd to n + 1, enter two integers Mi and Bi in each row. minimum output cost. sample input3 6 5
3 1
1 2
1 2 Sample output11hint

 

1 reduction in 1st urban teeth and 1 increase in 2nd urban teeth

 

Source

Silver

Question: after sorting, directly simulate it. Does it seem correct? Code:

 1 #include<cstdio> 2 #include<cstdlib> 3 #include<cmath> 4 #include<cstring> 5 #include<algorithm> 6 #include<iostream> 7 #include<vector> 8 #include<map> 9 #include<set>10 #include<queue>11 #include<string>12 #define inf 100000000013 #define maxn 5000014 #define maxm 500+10015 #define eps 1e-1016 #define ll long long17 #define pa pair<int,int>18 #define for0(i,n) for(int i=0;i<=(n);i++)19 #define for1(i,n) for(int i=1;i<=(n);i++)20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)22 #define mod 100000000723 using namespace std;24 inline int read()25 {26     int x=0,f=1;char ch=getchar();27     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}28     while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}29     return x*f;30 }31 int n,x,y,a[maxn],b[maxn],ans;32 int main()33 {34     freopen("input.txt","r",stdin);35     freopen("output.txt","w",stdout);36     n=read();x=read();y=read();37     for1(i,n)a[i]=read(),b[i]=read();38     sort(a+1,a+n+1);sort(b+1,b+n+1);39     for1(i,n)40      if(a[i]>b[i])ans+=y*(a[i]-b[i]);else ans+=x*(b[i]-a[i]);41     printf("%d\n",ans);42     return 0;43 }

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Bzoj3399: [usaco 2009 Mar] sand castle