Submission #104977

#	Time	Username	Problem	Language	Result	Execution time	Memory
104977		antimirage	Lamps (JOI19_lamps)	C++14	0 / 100	1069 ms	20048 KiB

lamp

    # include <bits/stdc++.h>
     
    using namespace std;
     
    const int N = 1e6 + 5;
     
    int n, dp[N][2], pref[N][2];
     
    string a, b;
     
    inline int calc (int l, int r, int type){
     
          if (type == 0)
                return pref[r][0] - pref[l - 1][0] + (b[l - 1] == b[l] && b[l] == '0');
     
          return pref[r][1] - pref[l - 1][1] + (b[l - 1] == b[l] && b[l] == '1');
    }
    main(){
     
          memset( dp, 0x3f3f3f3f, sizeof(dp) );
     
          cin >> n >> a >> b;
     
          a = ' ' + a;
          b = ' ' + b;
     
          for (int i = 1; i <= n; i++){
     
                if (b[i] != b[i - 1])
                      pref[i][ b[i] - 48 ] = 1;
     
                pref[i][0] += pref[i - 1][0];
                pref[i][1] += pref[i - 1][1];
          }
          dp[0][0] = 0;
     
          for (int i = 1; i <= n; i++){
     
                if (a[i] == b[i])
                      dp[i][0] = min( dp[i - 1][1], dp[i - 1][0] );
     
                if (a[i] != b[i])
                      dp[i][1] = min( dp[i - 1][1], dp[i - 1][0] + 1);
     
                for (int j = i; j >= 1; j--){
                      dp[i][0] = min( dp[i][0], dp[j - 1][0] + calc( j, i, 1 ) + 1 );
                      dp[i][0] = min( dp[i][0], dp[j - 1][0] + calc( j, i, 0 ) + 1 );
     
                      dp[i][1] = min( dp[i][1], dp[j - 1][1] + calc( j, i, 0 ) + 1 );
     
                      dp[i][1] = min( dp[i][1], dp[j - 1][0] + calc( j, i, 0 ) - (b[i] == '1') + 2 );
     
                      dp[i][1] = min( dp[i][1], dp[j - 1][1] + calc( j, i, 1 ) + 1 );
     
                      dp[i][1] = min( dp[i][1], dp[j - 1][0] + calc( j, i, 1 ) -  (b[i] == '0') + 2 );
                }
          }
          cout << min(dp[n][0], dp[n][1]) << endl;
    }
    /**
    13
    0001101001101
    0101100011011
     
    0001101001101
    0101101001101
    0101100000101
    0101100011011
    **/

Compilation message (stderr)

lamp.cpp:18:10: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
     main(){
          ^

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 4
• Subtask 4: 0 / 49