P1220 关路灯 （ 区间dp

#include 
using namespace std;
using VI = vector<int>;
using ll = long long;
using PII = pair<int,int>;
const int mod = 19650827;
int n,s;
int h[52];
int w[52];
int vis[52];
int sum[52];
int dp[1010][1010][2];
int res = 0x3f3f3f3f;
 
 
int main(){
    cin>>n>>s;
    for(int i=1;i<=n;i++){
        cin>>h[i]>>w[i];
        sum[i] = sum[i-1] + w[i];
    }
    memset(dp,0x3f,sizeof dp);
    dp[s][s][0] = 0;
    dp[s][s][1] = 0;
    for(int len=2;len<=n;len++){
        for(int i=1;i+len-1<=n;i++){
            int j = i + len - 1;
            dp[i][j][0] = min({dp[i+1][j][0] + (h[i+1]- h[i]) * (sum[i] + sum[n] - sum[j] ) ,
                                 dp[i+1][j][1] + (h[j]  - h[i]) * (sum[i] + sum[n] - sum[j])});
            dp[i][j][1] = min({dp[i][j-1][1] + (h[j]  - h[j-1]) * (sum[i-1] + sum[n] - sum[j-1]),
                                 dp[i][j-1][0] + (h[j]  - h[i])   * (sum[i-1] + sum[n] - sum[j-1])});
            //cout<
        }
 
    }
 
    cout<<min(dp[1][n][0],dp[1][n][1]);
 
}

和另一个题 Sue的小球基本一摸一样，

这种区间dp主要就是没有具体的区间了，都转化成了点点之间