Implemented longest common subsequence in C

dynamic_programing/longest_common_subsequence/C/long_comm_subs.c

@@ -0,0 +1,63 @@
+#include<stdio.h>
+#include<string.h>
+
+int i,j,m,n,c[20][20];
+char x[20],y[20],b[20][20];
+
+void print(int i,int j)
+{
+                if(i==0 || j==0)
+                                return;
+                if(b[i][j]=='c')
+                {
+                                print(i-1,j-1);
+                                printf("%c",x[i-1]);
+                }
+                else if(b[i][j]=='u')
+                                print(i-1,j);
+                else
+                                print(i,j-1);
+}
+
+void lcs()
+{
+                m=strlen(x);
+                n=strlen(y);
+                for(i=0;i<=m;i++)
+                                c[i][0]=0;
+                for(i=0;i<=n;i++)
+                                c[0][i]=0;
+
+                //c, u and l denotes cross, upward and downward directions respectively
+                for(i=1;i<=m;i++)
+                                for(j=1;j<=n;j++)
+                                {
+                                                if(x[i-1]==y[j-1])
+                                                {
+                                                                c[i][j]=c[i-1][j-1]+1;
+                                                                b[i][j]='c';
+                                                }
+                                                else if(c[i-1][j]>=c[i][j-1])
+                                                {
+                                                                c[i][j]=c[i-1][j];
+                                                                b[i][j]='u';
+                                                }
+                                                else
+                                                {
+                                                                c[i][j]=c[i][j-1];
+                                                                b[i][j]='l';
+                                                }
+                                }
+}
+
+int main()
+{
+                printf("Enter 1st sequence:");
+                scanf("%s",x);
+                printf("Enter 2nd sequence:");
+                scanf("%s",y);
+                printf("\nThe Longest Common Subsequence is ");
+                lcs();
+                print(m,n);
+        return 0;
+}