Create KMP.c

串/KMP.c

@@ -0,0 +1,68 @@
+#include<stdio.h>
+#include<stdlib.h>
+#include<stdbool.h>
+#define MAXLEN 255
+
+typedef struct{
+	char ch[MAXLEN];
+	int length;
+}SString;
+
+//输入字符串
+void assign(SString *S){
+	int i = 1;
+	char x;
+	scanf("%c",&x);
+	while(x!='\n'){
+		S->ch[i++] = x;
+		scanf("%c",&x);
+	}
+	S->length = i-1;
+}
+//打印字符串
+void print(SString S){
+	for(int i=1;i<=S.length;i++){
+		printf("%c",S.ch[i]);
+	}
+	printf("\n");
+}
+//求next数组
+void getNext(SString S,int *next){
+	next[1] = 0;
+	int i = 1,j = 0;
+	while(i<S.length){
+		if(j==0||S.ch[i]==S.ch[j]){
+			next[++i] = ++j;
+		}else{
+			j = next[j];
+		}
+	}
+}
+//kmp代码
+int KMP(SString S,SString T){
+	int i=1,j=1;
+	int next[T.length+1];
+	getNext(T,next);
+	while(i<=S.length&&j<=T.length){
+		if(j==0||S.ch[i]==T.ch[j]){
+			++i;
+			++j;
+		}else{
+			j = next[j];
+		}
+	}
+	if(j>T.length){
+		return i-T.length;
+	}else{
+		return 0;
+	}
+}
+int main(){
+	SString S,T;
+	printf("请输入主串：\n");
+	assign(&S);
+	printf("请输入模式串：\n");
+	assign(&T);
+	printf("匹配到的位置:%d",KMP(S,T));
+	return 0;
+}