30pts，求调

#include<bits/stdc++.h>
using namespace std;
#define int long long
vector<int> v;
signed main(){
    int c,T;
    cin>>c>>T;
    v.push_back(0);
    for(int op=1;op<=T;op++){
        int n,k;
        cin>>n>>k;
        int h;
        for(int i=1;i<=n;i++){
            cin>>h;
            v.push_back(h);
        }
        sort(v.begin(),v.end());
        int dp[n+1],b[n+1];
        b[1]=k;
        for(int i=2;i<=n;i++){
            b[i]=k-(v[i]-v[i-1]);
        }
        int max_sum=-99999;
        dp[0]=0;
        dp[1]=b[1];
        for(int j=1;j<=n;j++){
        dp[j] = max(b[j], dp[j-1] + b[j]);
        if (dp[j] > max_sum)
            max_sum = dp[j];
        }
        cout<<max_sum<<endl;
        v.clear();
        v.push_back(0);
        }
    return 0;
}