LuoGu: CF1200E Compress Words
CF: E. Compress Words
需要一个串的前缀和一个串的后缀匹配,用 KMP 不好思考。直接用字符串哈希。
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| #include <cstdio> #include <cstring> #include <algorithm> using namespace std; template <class Type> void read (Type &x) { char c; bool flag = false; while ((c = getchar()) < '0' || c > '9') c == '-' && (flag = true); x = c - '0'; while ((c = getchar()) >= '0' && c <= '9') x = (x << 1) + (x << 3) + c - '0'; flag && (x = ~x + 1); } template <class Type, class ...rest> void read (Type &x, rest &...y) { read(x), read(y...); } template <class Type> void write (Type x) { x < 0 && (putchar('-'), x = ~x + 1); x > 9 && (write(x / 10), 0); putchar('0' + x % 10); } typedef long long LL; const int N = 1e6 + 10; const int base = 131, ibase = 922042494, mod = 998244353; int s[N], t[N]; char c[N], ans[N]; int n, m, len, pbase[N]; int main () { pbase[0] = 1; for (int i = 1; i < N; ++i) pbase[i] = (LL)pbase[i - 1] * base % mod; read(n); for (int i = 1; i <= n; ++i) { scanf("%s", c + 1); m = strlen(c + 1); for (int k = 1; k <= m; ++k) t[k] = ((LL)c[k] * pbase[k] + t[k - 1]) % mod; for (int k = min(m, len); ~k; --k) if ((s[len] - s[len - k] + mod) % mod == (LL)t[k] * pbase[len - k] % mod) { for (int j = k + 1; j <= m; ++j) { ++len; ans[len] = c[j]; s[len] = ((LL)c[j] * pbase[len] + s[len - 1]) % mod; } break; } } for (int i = 1; i <= len; ++i) putchar(ans[i]); return 0; }
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