dijkstra.c

#include "dijkstra.h"

void dijkstra(int32_t *d, size_t V, Edge *es, size_t E, size_t s) {
	const int INF = INT32_MAX;
	bool used[V];
	for(size_t i = 0; i < V; i++) {
		used[i] = false;
		d[i] = INF;
	}

	d[s] = 0;

	while(true) {
		bool continueFlag = false;
		size_t v = V;
		for(int i = 0; i < V; i++) {
			if(!used[i] && (v == V || d[i] < d[v])) {
				v = i;
				continueFlag = true;
			}
		}
		
		if(!continueFlag)
			break;

		used[v] = true;

		for(int i = 0; i < E; i++) {
			if(es[i].from == v) {
				Edge e = es[i];
				if(d[e.from] + e.cost < d[e.to])
					d[e.to] = d[e.from] + e.cost;
			}
		}
	}
}

dijkstra.h

#include <stdlib.h>
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>

#ifndef DIJKSTRA_H
#define DIJKSTRA_H

typedef struct _Edge {
	size_t from, to;
	int32_t cost;
} Edge;

void dijkstra(int32_t *d, size_t V, Edge *es, size_t E, size_t s);

#endif