一、AcWing 902 最短编辑距离
1. 问题描述
2. 问题解决
#include
#include
using namespace std;
const int N = 1010;
int n, m;
char a[N], b[N];
int f[N][N];
int main()
{
scanf("%d%s", &n, a + 1);
scanf("%d%s", &m, b + 1);
for (int i = 0; i <= m; i ++ ) f[0][i] = i;
for (int i = 0; i <= n; i ++ ) f[i][0] = i;
for (int i = 1; i <= n; i ++ )
for (int j = 1; j <= m; j ++ )
{
f[i][j] = min(f[i - 1][j] + 1, f[i][j - 1] + 1);
if (a[i] == b[j]) f[i][j] = min(f[i][j], f[i - 1][j - 1]);
else f[i][j] = min(f[i][j], f[i - 1][j - 1] + 1);
}
printf("%dn", f[n][m]);
return 0;
}
二、AcWing 899. 编辑距离
1. 问题描述
2. 问题解决
#include
#include
#include
using namespace std;
const int N = 15, M = 1010;
int n, m;
int f[N][N];
char str[M][N];
int edit_distance(char a[], char b[])
{
int la = strlen(a + 1), lb = strlen(b + 1);
for (int i = 0; i <= lb; i ++ ) f[0][i] = i;
for (int i = 0; i <= la; i ++ ) f[i][0] = i;
for (int i = 1; i <= la; i ++ )
for (int j = 1; j <= lb; j ++ )
{
f[i][j] = min(f[i - 1][j] + 1, f[i][j - 1] + 1);
f[i][j] = min(f[i][j], f[i - 1][j - 1] + (a[i] != b[j]));
}
return f[la][lb];
}
int main()
{
scanf("%d%d", &n, &m);
for (int i = 0; i < n; i ++ ) scanf("%s", str[i] + 1);
while (m -- )
{
char s[N];
int limit;
scanf("%s%d", s + 1, &limit);
int res = 0;
for (int i = 0; i < n; i ++ )
if (edit_distance(str[i], s) <= limit)
res ++ ;
printf("%dn", res);
}
return 0;
}
三、蓝桥杯十一届
1. 问题描述
2. 问题解决
#include
#include
using namespace std;
constexpr size_t MAXN = 5e3;
int dp[MAXN][27];
int v;
signed main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
memset(dp, 0x80, sizeof dp), dp[0][0] = 0;
cin >> v;
for (int i = 1; i < MAXN; i++)
for (int j = 1; j <= 26; j++)
for (int k = 0; k < i; k++)
dp[i][j] = max(dp[i][j], dp[k][j - 1] + k * (i - k));
int i = 0, j = 0, same = 0, flag = 1;
while (flag) {
j = 1, i++;
for (; j <= 26; j++) {
if (dp[i][j] >= v) { flag = 0; break; }
}
}
while (i) {
if (j == 1)
cout << (char)'a';
else if (dp[i][j - 1] >= v)
j--, cout << (char)(j + 'a' - 1), v -= i - 1, same = 1;
else
cout << (char)(j + 'a' - 1), v -= i - 1 - same, same++;
i--;
}
}