Submission #331058

#	Time	Username	Problem	Language	Result	Execution time	Memory
331058		lohacho	Lamps (JOI19_lamps)	C++14	100 / 100	265 ms	21996 KiB

lamp

#include <bits/stdc++.h>

using namespace std;

using LL = long long;
const int MOD = (int)1e9 + 7;
const int NS = (int)1e6 + 4;
int N;
int A[NS], B[NS];
int dp[NS][3];

int cha(int x, int y){
    if(y != 2){
        return y;
    }
    return x;
}

int main(){
    scanf("%d", &N);
    for(int i = 1; i <= N; ++i){
        scanf("%1d", A + i);
    }
    for(int i = 1; i <= N; ++i){
        scanf("%1d", B + i);
    }
    for(int i = 0; i < NS; ++i){
        for(int j = 0; j < 3; ++j){
            dp[i][j] = MOD;
        }
    }
    dp[1][2] = 0;
    for(int i = 1; i <= N; ++i){
        for(int last = 0; last < 3; ++last){
            for(int now = 0; now < 3; ++now){
                int cost = 0;
                if(last != now && now != 2){
                    ++cost;
                }
                if((i == 1 || cha(A[i - 1], last) == B[i - 1]) && (cha(A[i], now) != B[i])){
                    ++cost;
                }
                dp[i + 1][now] = min(dp[i + 1][now], cost + dp[i][last]);
            }
        }
    }
    printf("%d", min({dp[N + 1][0], dp[N + 1][1], dp[N + 1][2]}));
    return 0;
}

Compilation message (stderr)

lamp.cpp: In function 'int main()':
lamp.cpp:20:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   20 |     scanf("%d", &N);
      |     ~~~~~^~~~~~~~~~
lamp.cpp:22:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   22 |         scanf("%1d", A + i);
      |         ~~~~~^~~~~~~~~~~~~~
lamp.cpp:25:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |         scanf("%1d", B + i);
      |         ~~~~~^~~~~~~~~~~~~~

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