foo.cpp: In function 'int main()':
foo.cpp:15:17: error: 'v' was not declared in this scope
     if (w[i] <= v)  f[i][v] = max(f[i-1][v],f[i-1][v-w[i]]+c[i]);
                 ^
foo.cpp:9:17: warning: unused variable 'n' [-Wunused-variable]
     int i,t,m,j,n;
                 ^