文本比较算法Ⅱ——Needleman/Wunsch算法的C++实现【求最长公共子串（不需要连续）】

算法见：http://www.cnblogs.com/grenet/archive/2010/06/03/1750454.html

 

求最长公共子串（不需要连续）

#include <stdio.h>
#include <string>
#define N 100


int max(int a, int b, int c){
    return (a>b?a:b)>c?(a>b?a:b):c;
}

int needleman(char s1[], char s2[]){
    int len1 = strlen(s1);
    int len2 = strlen(s2);
    int i,j;
    int count[N][N];
    for(i=0;i<len1+1;i++){
        count[i][0] = 0;
    }
    for(i=0;i<len2+1;i++){
        count[0][i] = 0;
    }
    for(i=1;i<len1+1;i++){
        for(j=1;j<len2+1;j++){
            if(s1[i] == s2[j]){
                count[i][j] = count[i-1][j-1]+1;
            } else {
                count[i][j] = max(count[i-1][j-1],count[i][j-1],count[i-1][j]);
            }
        }
    }
    return count[len1][len2];
}

int main(){
    char s1[N];
    char s2[N];
    while(scanf("%s%s",s1,s2)!=EOF){
        int result = needleman(s1,s2);
        printf("%d\n",result);
    }
    return 0;
}