只确定除了状态量, 没想出状态方程, 这道题的难度还是挺大的.下面是别人的解题报告:
http://par.cse.nsysu.edu.tw/~advprog/advprog2008/11081.doc
代码:
#include<stdio.h> #include<string.h> #define MAXN 65 int n; char s1[MAXN], s2[MAXN], s3[MAXN]; int f1[MAXN][MAXN][MAXN], f2[MAXN][MAXN][MAXN], f[MAXN][MAXN][MAXN]; void solve() { int len1 = strlen(s1+1); int len2 = strlen(s2+1); int len3 = strlen(s3+1); memset(f1,0,sizeof(f1)); memset(f2,0,sizeof(f2)); memset(f,0,sizeof(f)); for(int i = 0; i <= len1; i ++) for(int j = 0; j <= len2; j ++) f[i][j][0] = 1, f1[i][j][0] = 1, f2[i][j][0] = 1; for(int k = 1; k <= len3; k ++) { for(int i = 0; i <= len1; i ++) { for(int j = 0; j <= len2; j ++) { if(i)//第一串不为空 { f1[i][j][k] = f1[i-1][j][k]; if(s1[i] == s3[k]) f1[i][j][k] += f[i-1][j][k-1]; f1[i][j][k] %= 10007; } if(j)//第二串不为空 { f2[i][j][k] = f2[i][j-1][k]; if(s2[j] == s3[k]) f2[i][j][k] += f[i][j-1][k-1]; f2[i][j][k] %= 10007; } f[i][j][k] = (f1[i][j][k] + f2[i][j][k])%10007; } } } printf("%d\n",f[len1][len2][len3]); } void init() { while(~scanf("%d",&n)) while(n --) { scanf("%s%s%s", s1+1,s2+1,s3+1); solve(); } } int main() { init(); return 0; }