您的答案為: 22
正確答案為: 23

我也這樣...

#include<stdio.h>
#include<string.h>

char ans[101];
short lcs(char s1[],char s2[]){
    short dp[101][101] = {0},route[101][101] = {0},i,j,l1 = strlen(s1),l2 = strlen(s2);
    for(i=1;i<=l1;i++){
        for(j=1;j<=l2;j++){
            if(s1[i-1]==s2[j-1]){
                dp[i][j] = dp[i-1][j-1]+1;
                route[i][j] = 1;
            }
            else{
                if(dp[i-1][j]>dp[i][j-1]){
                    dp[i][j] = dp[i-1][j];
                    route[i][j] = 2;
                }
                else{
					dp[i][j] = dp[i][j-1];
                    route[i][j] = 3;
                }
            }
        }
    }
    int x = l1,y = l2,l3 = dp[l1][l2];
    ans[l3--] = '\0';
    while(x>0&&y>0){
        switch(route[x][y]){
		case 1:
            ans[l3--] = s1[x-1];
            x--;
            y--;
		break;
		case 2:
            x--;
		break;
		case 3:
            y--;
		break;
        }
    }
    return dp[l1][l2];
}

int main(){
    char s1[101],s2[101],s3[101];
    while(scanf("%s%s%s",s1,s2,s3)!=EOF){
        short s1s2,anss3;
        s1s2 = lcs(s1,s2);
        strcpy(s1,ans);
        anss3 = lcs(s1,s3);
        printf("%hd\n",anss3);
    }
}

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