D - Takahashi's Solitaire

https://atcoder.jp/contests/abc277/tasks/abc277_d

思路

先计算所有的输入的和 total，

将输入列表首先进行排列

找到所有连续段和中最大的值 maxsum， 此处连续满足条件 a[i] == a[i+1] 或者 a[i] + 1 == a[i+1]

最后 total - maxsum 即期望值。

Code

https://atcoder.jp/contests/abc277/submissions/36454757

long long n, m;
vector<long long> a;
 
int main()
{
    cin >> n >> m;
    
    long long totalsum = 0;
    
    for(int i=0; i<n; i++){
        int temp;
        cin >> temp;
        a.push_back(temp);
        
        totalsum += temp;
    }
 
    sort(a.begin(), a.end());
    
    int continous = true;
    
    for(int i=0; i<n-1; i++){
        if (a[i] == a[i+1]
        || a[i] + 1 == a[i+1]){
            continue;
        } else {
            continous = false;
            break;
        }
    }
    
    if (continous == true){
        cout << 0 << endl;
        return 0;
    }
 
    long long maxsum = -1;
 
    int size = a.size();
    int last_index = size - 1;
    int first_index = 0;
 
    // treat first_index position
    long long zsum = 0;
    int zv = a[0];
    zsum += zv;
    first_index++;
    
    int ii = first_index;
    while(a[ii] == a[ii - 1]
    || a[ii] == a[ii - 1] + 1){
        zsum += a[ii];
        ii++;
        first_index++;
    }
    
    if (zv == 0){
        int lv = a[last_index];
        if ((lv + 1) % m == 0){
            zsum += lv;
            last_index--;
            
            int ii = last_index;
            while(a[ii] == a[ii+1]
            || a[ii] + 1 == a[ii+1]){
                zsum += a[ii];
                ii--;
                last_index--;
            }
        }
    }
    
    if (maxsum < zsum){
        maxsum = zsum;
    }
 
    while(first_index <= last_index){
        // search continium towards
        long long csum = 0;
        int cv = a[first_index];
        csum += cv;
        first_index++;
 
        if (first_index > last_index){
            if (maxsum < csum){
                maxsum = csum;
            }
 
            break;
        }
 
        int ii = first_index;
        while(a[ii] == a[ii - 1]
        || a[ii] == a[ii - 1] + 1){
            csum += a[ii];
            first_index++;
            ii++;
        }
        
        if (maxsum < csum){
            maxsum = csum;
        }
    }
 
    cout << totalsum - maxsum << endl;
 
    return 0;
}