TopcoderSRM698Div1250RepeatString(dp)

题意

[题目链接]这怎么发链接啊。。。。。

Sol

枚举一个断点，然后类似于LIS一样dp一波

这个边界条件有点迷啊。。fst了两遍。。。

#includeusing namespace std;const int MAXN = 1e5 + 10, INF = 1e9 + 7;inline int read() {    char c = getchar(); int x = 0, f = 1;    while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();    return x * f;}int N, f[101][101];class RepeatString{public:    int solve(int pos, string s) {        string a, b; a += '.'; b += '*';        memset(f, 0x3f, sizeof(f));        for(int i = 0; i < pos; i++) a += s[i];        for(int i = pos; i < N; i++)  b += s[i];               int la = a.length() - 1, lb = b.length() - 1;        f[0][0] = 0;        for(int i = 0; i <= la; i++) f[i][0] = i;        for(int i = 0; i <= lb; i++) f[0][i] = 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 minimalModify(string s) {        N = s.length(); int ans = N;        for(int i = 0; i < N; i++) ans = min(ans, solve(i, s));        return ans;    }};int main() {    string s;     cin >> s;    cout << RepeatString().minimalModify(s);}/*pkafkbeabccfjejkdgkaatcedaocgmecaapakfvbfgefr*/