foo.c

#include<stdio.h>
#define M 5
#define N 6
int max(a,b){
    return a>=b?a:b;
}
int main(){
    int x[M] = { 1, 1, 2, 3, 2 };
    int y[N] = { 2, 2, 4, 3, 1, 2 };
    int c[M][N];
    
    int i,j;
    
    for(i=0;i<M;i++){
        for(j=0;j<N;j++){
            if(i == 0 || j ==0){
                c[i][j] = 0;
            }else if(x[i] == y[j]){
                c[i][j] = c[i-1][j-1] + 1;
            }else if(x[i] != y[j]){
                c[i][j] = max(c[i-1][j],c[i][j-1]);
            }
        }
    }
    
    for(i=0;i<M;i++){
        for(j=0;j<N;j++){
            printf("%d\t",c[i][j]);
        }
        printf("\n");
    }
    
}