#include <bits/stdc++.h> using namespace std; int N; int A[1010101]; int B[1010101]; int D[1010101][5], ans=1234567890; int C[5][5] ={ {0, 1, 1, 2, 2}, {0, 0, 1, 1, 2}, {0, 1, 0, 2, 1}, {0, 0, 1, 0, 2}, {0, 1, 0, 2, 0} }; int tog(int p, int o){ int x = A[p]; if (o == 1 || o == 4) x = 0; else if (o == 2 || o == 3) x = 1; return (x != B[p]) ? 1 : 0; } 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]); memset(D, 1, sizeof D); D[0][0] = 0; for (int i=1; i<=N; i++) for (int j=0; j<5; j++) for (int k=0; k<5; k++) { D[i][k] = min(D[i][k], D[i-1][j] + C[j][k] + max(0, tog(i, k)-tog(i-1, j))); } for (int i=0; i<5; i++) ans = min(ans, D[N][i]); printf("%d\n", ans); return 0; }

lamp.cpp: In function 'int main()':
lamp.cpp:24:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
     ~~~~~^~~~~~~~~~
lamp.cpp:25:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (int i=1; i<=N; i++) scanf("%1d", &A[i]);
                              ~~~~~^~~~~~~~~~~~~~
lamp.cpp:26:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for (int i=1; i<=N; i++) scanf("%1d", &B[i]);
                              ~~~~~^~~~~~~~~~~~~~