这是
个有个性
算法
他两位提出者都是Turing奖获得者.:)基本
思想就是把
串映射成个
值指纹
Hash...但是text太大
时候预处理时间也是得考虑进来~不过最坏时候也就和平凡算法样了(还可能更坏吗...)#
<stdlib.h>#
<stdio.h>#
<
.h>void usage(char * prog)
{
pr
f(\"Usage: %s text pattern\\n\", prog);exit(123);
}
/*Algorithm~*/
void rk_sm(char * patt, char * text,
patt_length, text_length, c, q){
p = 0, t = 0;long long h = 1;
i, k, s; flag;for(i = 0; i <= patt_length -1; i
)h *= c;
h = h % q;
for(i = 0; i < patt_length; i
){
p = (c * p + patt[i])%q;
t = (c * t + text[i])%q;
}
for(s = 0; s < text_length - patt_length + 1; s
){
(p 
t){
flag = 1;
for(i = 0; i < patt_length; i
)(patt[i] != text[s+i])flag = 0; //
flag, not match...[Page]
(flag){
pr
f(\"position %d\\n\", s);pr
f(\"text: %s\\n\", text);pr
f(\"patn: \");for(k = 1; k <= s; k
)pr
f(\" \");pr
f(\"%s\\n\", patt);
;}
}
(s < text_length - patt_length)
t = (c * (t - text[s]* h) + text[s + patt_length])%q;
}
pr
f(\"Not match!\\n\");}
( argc, char * argv
){
char * text = NULL;
char * pattern = NULL;
[Page]
(argc != 3)usage(argv[0]);
{
text = argv[1];
pattern = argv[2];
}
pr
f(\"text: %s\\n\", text);pr
f(\"patn: %s\\n\", pattern);rk_sm(pattern, text, strlen(pattern), strlen(text), 26, 13);
1;}
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