Submission #1054187

#	Time	Username	Problem	Language	Result	Execution time	Memory
1054187		chaoslong	Lamps (JOI19_lamps)	C++14	100 / 100	44 ms	33732 KiB

lamp

// Calm down.
// Think three times, code twice.
#include "bits/stdc++.h"
#define forr(_a,_b,_c) for(int _a = (_b); _a <= (_c); ++_a)
#define ford(_a,_b,_c) for(int _a = (_b) + 1; _a --> (_c);)
#define forf(_a,_b,_c) for(int _a = (_b); _a < (_c); ++_a)
#define st first
#define nd second
#define ll long long
#define ull unsigned long long
#define pii pair <int,int>
#define pll pair <ll,ll>
#define piii pair <int,pii>
#define vi vector <int>
#define pb push_back
#define mp make_pair
#define all(x) begin(x),end(x)
#define mask(i) (1LL << (i))
#define bit(x, i) (((x) >> (i)) & 1)
#define bp __builtin_popcountll
#define file "test"

using namespace std;
const int N = 1e6 + 5;
const int mod = 1e9 + 7; // 998244353
const ll oo = 1e18;

int n;
int a[N], b[N];
int dp[N][3][2];

void to_nho_cau() {
    cin >> n;
    int dem1 = 0, dem0 = 0;
    forr(i, 1, n) {
        char x; cin >> x;
        a[i] = (x == '1') ? 1: 0;
    }
    forr(i, 1, n) {
        char x; cin >> x;
        b[i] = (x == '1') ? 1: 0;
    }
    memset(dp, 0x3f, sizeof dp);
    dp[0][0][0] = 0;
    forr(i, 1, n) {
        forr(j, 0, 2) {
            forr(k, 0, 1) {
                //j = 0 là giữ nguyên giá trị ban đầu
                //  = 1 là chuyển thành 0
                //  = 2 là chuyển thành 1
                //k = 0 nghĩa là đảo tại vị trí này
                int val = a[i];
                if(j == 1) val = 0;
                if(j == 2) val = 1;
                if(k == 1) val ^= 1;
                if(val != b[i]) continue;
                forr(j2, 0, 2) {
                    forr(k2, 0, 1) {
                        dp[i][j][k] = min(dp[i][j][k], dp[i-1][j2][k2] + (j > 0 && j != j2) + (k > 0 && k != k2));
                    }
                }
            }
        }
    }
    int ans = mod;
    forr(j, 0, 2) {
        forr(k, 0, 1) {
            ans = min(ans, dp[n][j][k]);
        }
    }
    cout << ans << "\n";
}

signed main(){
    ios_base::sync_with_stdio(0);cin.tie(0);
    #ifdef LOCAL
        freopen(file".inp","r",stdin);
        freopen(file".out","w",stdout);
    #endif
    int t = 1;
    //cin >> t;
    while(t--) to_nho_cau();
}
/*
1.self check:
2.long long
3.size of array
4.code for testing
5.initializing
6.modulo number
*/
/**
  ∧__∧
（｀•ω• )づ__∧
（つ　 /( •ω•。)
  しーＪ (nnノ) pat pat
**/
/**  /\_/\
*   (= ._.)
*   / >☕ \>💻
**/
/**
･*･  ∧,,∧ ∧_∧   ･*･
'.　 ( ｡･ω･)(･ω･｡ )　  .'
　'･ |   つ♥と    |.･'
      *'***** '*
**/

Compilation message (stderr)

lamp.cpp:98:9: warning: "/*" within comment [-Wcomment]
   98 | /**  /\_/\
      |          
lamp.cpp: In function 'void to_nho_cau()':
lamp.cpp:34:9: warning: unused variable 'dem1' [-Wunused-variable]
   34 |     int dem1 = 0, dem0 = 0;
      |         ^~~~
lamp.cpp:34:19: warning: unused variable 'dem0' [-Wunused-variable]
   34 |     int dem1 = 0, dem0 = 0;
      |                   ^~~~

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