模板题,,,模板打错查了1h+QAQ
#include<cmath> #include<cstdio> #include<cstring> #include<algorithm> using namespace std; const int N = 1000003; int t1[N], t2[N], c[N], f[N][30]; void st(int *x, int *y, int *sa, int n, int m) { int i; for(i = 0; i < m; ++i) c[i] = 0; for(i = 0; i < n; ++i) ++c[x[y[i]]]; for(i = 1; i < m; ++i) c[i] += c[i - 1]; for(i = n - 1; i >= 0; --i) sa[--c[x[y[i]]]] = y[i]; } void mkhz(int *a, int *sa, int n, int m) { int *t, *x = t1, *y = t2, i, j, p; for(i = 0; i < n; ++i) x[i] = a[i], y[i] = i; st(x, y, sa, n, m); for(j = 1, p = 1; p < n; j <<= 1, m = p) { for(p = 0, i = n - j; i < n; ++i) y[p++] = i; for(i = 0; i < n; ++i) if (sa[i] >= j) y[p++] = sa[i] - j; st(x, y, sa, n, m); // for(i = 1; i < n; ++i) printf("%d ", sa[i]); puts(""); for(t = x, x = y, y = t, p = 1, x[sa[0]] = 0, p = 1, i = 1; i < n; ++i) x[sa[i]] = y[sa[i]] == y[sa[i - 1]] && y[sa[i] + j] == y[sa[i - 1] + j] ? p - 1 : p++; } } void mkh(int *r, int *sa, int *rank, int *h, int n) { int k = 0, i, j; for(i = 1; i <= n; ++i) rank[sa[i]] = i; for(i = 1; i <= n; h[rank[i++]] = k) for(k ? k-- : 0, j = sa[rank[i] - 1]; r[i + k] == r[j + k]; ++k); } void mkst(int *h, int n) { int k = floor(log((double)n) / log(2.0)); for(int i = 1; i <= n; ++i) f[i][0] = h[i]; for(int j = 1; j <= k; ++j) for(int i = 1; i <= n; ++i) { if (i + (1 << j) - 1 > n) break; f[i][j] = min(f[i][j - 1], f[i + (1 << (j - 1))][j - 1]); } } char s[N]; int n, sa[N], a[N], rank[N], h[N]; int rmq(int l, int r) { l = rank[l]; r = rank[r]; if (l > r) swap(l, r); ++l; int k = floor(log((double)(r - l + 1)) / log(2.0)); return min(f[l][k], f[r - (1 << k) + 1][k]); } int main() { while (scanf("%s", s + 1) != EOF) { n = strlen(s + 1); for(int i = 1; i <= n; ++i) a[i] = s[i]; a[n + 1] = 126; for(int i = 1; i <= n; ++i) a[n + 1 + i] = a[n + 1 - i]; mkhz(a, sa, n * 2 + 2, 130); mkh(a, sa, rank, h, n * 2 + 1); mkst(h, n * 2 + 1); // for(int i = 1; i <= n * 2 + 1; ++i) printf("%d ", sa[i]); puts(""); // for(int i = 1; i <= n * 2 + 1; ++i) printf("%d ", rank[i]); puts(""); int ans = 0, x, h, t; for(int i = 1; i <= n; ++i) { // ans = max(ans, rmq(i, 2 * n + 2 - i) * 2 - 1); // if (i != 1 && a[i - 1] == a[i]) ans = max(ans, rmq(i, 2 * n + 3 - i) * 2); if ((x = rmq(i, 2 * n + 2 - i)) * 2 - 1 > ans) ans = x * 2 - 1, h = i - x + 1, t = i + x - 1; if (i != 1 && a[i - 1] == a[i] && (x = rmq(i, 2 * n + 3 - i)) * 2 > ans) ans = x * 2, h = i - x , t = i + x - 1; // printf("%d ", ans); } for(int i = h; i <= t; ++i) putchar(s[i]); puts(""); // printf("%d ", ans); } return 0; }
第一次把调试信息放在代码里,会不会显得我很制杖呢?(水题都调了这么多)