Submission #1694885

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Source Code Expand

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

const int MAX_N = 1000005;

char S[MAX_N], T[MAX_N];
int N, pos[MAX_N], R[MAX_N], f[MAX_N];

int main() {
  scanf("%d%s%s", &N, S + 1, T + 1);
  int l = 0, r = N, res = 0;
  
  for (int i = N, l = N; i; --i) {
    if (l > i) l = i;
    while (l > 0 && S[l] != T[i]) l--;
    pos[i] = l;
  }

  for (int i = 1; i <= N; ++i)
    R[pos[i]] = i;
  
  if (R[0]) {
    puts("-1");
    return 0;
  }

  for (int i = N; i; --i) {
    int val = -1;
    for (int j = i + 1; j <= R[i]; ++j) val = max(val, f[j]);
    f[i] = val + 1;
    res = max(res, f[i]);
  }

  printf("%d\n", res);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:12:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%s%s", &N, S + 1, T + 1);
                                    ^

Judge Result