Adding solution for 1436

C/1436.c

@@ -0,0 +1,110 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+char *
+destCity(char*** paths, int pathsSize, int* pathsColSize) {
+    struct {
+        char **data;
+        unsigned long size;
+        unsigned long cap;
+    } froms = {0};
+    struct {
+        char **data;
+        unsigned long size;
+        unsigned long cap;
+    } tos = {0};
+
+    froms.cap = pathsSize;
+    froms.data = calloc(froms.cap, sizeof(*froms.data));
+
+    tos.cap = pathsSize;
+    tos.data = calloc(tos.cap, sizeof(*tos.data));
+
+    for ( int i = 0; i < pathsSize; ++i ) {
+        froms.data[froms.size++] = paths[i][0];
+        tos.data[tos.size++] = paths[i][1];
+    }
+
+    char *ret = NULL;
+    for ( unsigned long i = 0; i < tos.size; ++i ) {
+        bool found = false;
+        for ( unsigned long j = 0; j < froms.size; ++j ) {
+            if ( strcmp(tos.data[i], froms.data[j]) == 0 ) {
+                found = true;
+                break;
+            }
+        }
+        if ( ! found ) { ret = tos.data[i]; break; }
+    }
+
+    (void) pathsColSize;
+
+    free(tos.data);
+    free(froms.data);
+
+    return ret;
+}
+
+char *
+paths_to_cstr_temp(char ***paths, int pathsSize) {
+    static char *data = NULL;
+    static unsigned long size = 0;
+    static unsigned long cap = 1024;
+
+    if ( data == NULL ) { data = malloc(sizeof(char) * (cap + 1)); }
+    size = 0;
+    memset(data, 0, cap);
+
+    data[size++] = '[';
+    for ( int i = 0; i < pathsSize; ++i ) {
+        if ( size + 32 >= cap ) { cap = cap*2; data = realloc(data, cap*2); }
+
+        if ( i > 0 ) { data[size++] = ','; }
+        data[size++] = '[';
+        char *from = paths[i][0];
+        while ( *from != '\0' ) { data[size++] = *from++; }
+        data[size++] = ',';
+        char *to = paths[i][1];
+        while ( *to != '\0' ) { data[size++] = *to++; }
+        data[size++] = ']';
+    }
+    data[size++] = ']';
+    data[size++] = '\0';
+
+    return data;
+}
+
+void
+r(char ***paths, int pathsSize, char *exp)
+{
+    printf("destCity(%s, %d) = %s | exp: %s\n",
+           paths_to_cstr_temp(paths, pathsSize),
+           pathsSize,
+           destCity(paths, pathsSize, NULL),
+           exp);
+}
+
+int
+main(void)
+{
+
+    char *paths11[2] = {"London","New York"};
+    char *paths12[2] = {"New York","Lima"};
+    char *paths13[2] = {"Lima","Sao Paulo"};
+    char **paths1[] = {paths11, paths12, paths13};
+    r(paths1, 3, "Sao Paulo");
+
+    char *paths21[2] = {"B","C"};
+    char *paths22[2] = {"D","B"};
+    char *paths23[2] = {"C","A"};
+    char **paths2[] = {paths21, paths22, paths23};
+    r(paths2, 3, "A");
+
+    char *paths31[2] = {"A","Z"};
+    char **paths3[] = {paths31};
+    r(paths3, 1, "Z");
+
+    return 0;
+}