View Compilation Error

0_0_16362661_6654.c:14:9: error: unknown type name 'node'
 int dit(node a,node b){
         ^
0_0_16362661_6654.c:14:16: error: unknown type name 'node'
 int dit(node a,node b){
                ^
0_0_16362661_6654.c: In function 'DFS':
0_0_16362661_6654.c:21:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for (int y = 1;y <= ny;y ++)
     ^
0_0_16362661_6654.c:21:5: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_16362661_6654.c: In function 'KM':
0_0_16362661_6654.c:50:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for (int x = 1;x <= nx;x ++)
     ^
0_0_16362661_6654.c:59:13: error: expected expression before 'int'
             int d = inf;
             ^
0_0_16362661_6654.c:61:31: error: 'd' undeclared (first use in this function)
                 if (!visy[i]&&d > slack[i])
                               ^
0_0_16362661_6654.c:61:31: note: each undeclared identifier is reported only once for each function it appears in