Mathematical Curse（dp）

​​Mathematical Curse - 题库 - 计蒜客​​

记得是要记录最小值，max有可能是从最小反转zu过来

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<vector>
#include<queue>
#include<set>
#define mem(a,x) memset(a,x,sizeof(a))
#define s1(x) scanf("%d",&x)
#define s2(x,y) scanf("%d%d",&x,&y)
#define s3(x,y,z) scanf("%d%d%d",&x,&y,&z)
#define s4(x,y,z,k) scanf("%d%d%d%d",&x,&y,&z,&k)
#define ff(a,n) for(int i = 0 ; i < n; i++) scanf("%d",a+i)
#define ls 2*rt
#define rs 2*rt+1
#define lson ls,L,mid
#define rson rs,mid+1,R
#define ll long long
using namespace std;
typedef pair<int,int> pii;
//inline ll ask(int x){ll res=0;while(x)res+=c[x],x-=x&(-x);return res;}
//inline void add(int x,int d){while(x<=n)c[x]+=d,x+=x&(-x);}
//int gcd(int a, int b) { return b == 0 ? a : gcd(b, a%b);}
const ll inf = 1e18;
const int mx = 1e3+6;
//const int mod = 1e9+6;
int n,m,k,num[mx];
ll Max[7],Min[7];
char s[10];
ll calc(ll a,int b, int x){
  if( s[x] == '+')
    return a+b;
  if( s[x] == '-')
    return a-b;
  if( s[x] == '*')
    return a*b;
  if( s[x] == '/')
    return a/b;
}
int main(){
  //  freopen("C:\\Users\\black\\Desktop\\in.txt","r",stdin);
  int T=10;  scanf("%d",&T);
  while(T--){
    s3(n,m,k);
    for(int i = 0; i < n; i++){
      scanf("%d",num+i);
    }
    scanf("%s",s+1); 
    for(int i = 0; i <6; i++){
      Max[i] = -inf;
      Min[i] = inf;
    }
    Max[0]=Min[0]=k;
  //  cout<<Max[0]<<endl;
    ll t1,t2;
    for(int i = 0; i < n; i++){
      for(int k = m; k >= 1; k--){
        //printf("k =%d  %lld\n",k,Max[k-1]);
        if(Max[k-1]!=-inf){
        //  puts("jin");
          t1 = calc(Max[k-1],num[i],k);
          t2 = calc(Min[k-1],num[i],k);
          Max[k] = max(max(t1,t2),Max[k]);
          Min[k] =min(min(t1,t2),Min[k]);  
          //printf("k =%d  %lld\n",k,Max[k]);
        }
      
      }
    }
    printf("%lld\n",Max[m]);  
  
  }
  


  return 0;
}