50 lines
927 B
Plaintext
50 lines
927 B
Plaintext
public static int bF(String a,String b) {
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int m=a.length(),n=b.length(),k;
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char[] a1=a.toCharArray();
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char[] b1=b.toCharArray();
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for(int i=0;i<=m-n;i++) {
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k=0;
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for(int j=0;j<n;j++) {
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if(a1[i+j]==b1[j]) {
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k++;
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}
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else
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break;
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}
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if(k==n) {
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return i;
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}
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}
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return -1;
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}
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public static int rK(String a,String b) {
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int m=a.length(),n=b.length(),s,j;
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int[] hash=new int[m-n+1];
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int[] table=new int[26];
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char[] a1=a.toCharArray();
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char[] b1=b.toCharArray();
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s=1;
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//将26的次方存储在一个表里，取的时候直接用,虽然溢出，但没啥问题
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for(j=0;j<26;j++) {
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table[j]=s;
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s*=26;
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}
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for(int i=0;i<=m-n;i++) {
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s=0;
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for(j=0;j<n;j++) {
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s+=(a1[i+j]-'a')*table[n-1-j];
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}
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hash[i]=s;
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}
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s=0;
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for(j=0;j<n;j++) {
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s+=(b1[j]-'a')*table[n-1-j];
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}
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for(j=0;j<m-n+1;j++) {
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if(hash[j]==s) {
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return j;
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}
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}
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return -1;
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}
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