Submission #979572

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Source Code Expand

#include <cstdio>
#include <algorithm>
int const N = 1234567;

int last[N][26];
int s[N], t[N];
int main() {
  int n;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    int c = getchar();
    while (c <= 32) c = getchar();
    s[i] = c - 'a';
  }
  for (int i = 0; i < n; i++) {
    int c = getchar();
    while (c <= 32) c = getchar();
    t[i] = c - 'a';
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < 26; j++) {
      last[i][j] = i > 0 ? last[i - 1][j] : -1;
    }
    last[i][s[i]] = i;
  }
  int cur = n - 1;
  int curAns = 0;
  int ans = 0;
  for (int i = n - 1; i >= 0; ) {
    int letter = t[i];
    int prev = last[cur][letter];
    if (prev == i) {
      i--;
      cur--;
      continue;
    }
    if (prev < 0) {
      puts("-1");
      return 0;
    }
    while (i > prev && t[i - 1] == letter) --i;
    ++curAns;
    ans = std::max(ans, curAns);
    if (i == prev) {
      curAns = 0;
    }
    i--;
    cur = prev - 1;
  }
  printf("%d\n", ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:9:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
                  ^

Judge Result