#include <stdio.h>
#include <stdlib.h>

#define NIL_VERTEX -1
#define DENOTE_INF_COST -1
#define COMP_INF_COST 100008

// translate 1-origin into 0-origin
int i0O(int index1Origin) {
    return index1Origin-1;
}


#include <stdio.h>
#include <stdlib.h>

#define MAX_NUM_STACK_VALUES 100
#define STR_MAX_LENGTH 100

typedef enum {
    WHITE,
    GRAY,
    BLACK
} Color;

typedef struct {
    struct Vtx * vertex;
//    int iVertex;
    int weight;
} ArrowTo;

int isNullArrow(ArrowTo a) {
//    return iVertex == NIL_VERTEX;
    return a.vertex == NULL;
}

typedef struct Vtx {
    ArrowTo * adjList;
    Color color;
    int discoveryCost;
    struct Vtx * discoverFrom;
    int key;
} Vertex;

void 
dijkstra(
        Vertex vertices[], 
        int nVertices,
        int startingVertexIndex
) {
    int mincost, u, v, i;
    
    for (i = 0; i < nVertices; i++) {
        vertices[i].discoveryCost = COMP_INF_COST;
        vertices[i].discoverFrom = NULL;
        vertices[i].color = WHITE;
    }
    
    vertices[startingVertexIndex].discoveryCost = 0;
    
    while (1) {
        mincost = COMP_INF_COST;
        
        for (i = 0; i < nVertices; i++) // for each vertex
            if (vertices[i].color != BLACK && vertices[i].discoveryCost < mincost)
                mincost = vertices[u = i].discoveryCost;
        
        if (mincost == COMP_INF_COST) break;
        
        vertices[u].color = BLACK;
        
        for (v = 0; !isNullArrow(vertices[u].adjList[v]); v++) {// for each in adjList
            i = vertices[u].discoveryCost + vertices[u].adjList[v].weight;

            if (vertices[u].adjList[v].vertex->color != BLACK && i < vertices[u].adjList[v].vertex->discoveryCost) {
                vertices[u].adjList[v].vertex->discoverFrom = &vertices[u];
                vertices[u].adjList[v].vertex->discoveryCost = i;
            }
        }
        
    }
}

int main(int argc, char** argv) {
    int nVertices, i, j;
    
    // scan number of already existed events
    scanf("%d", &nVertices); 
    
//    // adjMatrix ----------------------------
//    int ** adjMatrix;
//    
//    adjMatrix = (int **)malloc(nVertices * sizeof(int *));
//    
//    for (i = 0; i < nVertices; i++) {
//        adjMatrix[i] = (int *)malloc(nVertices * sizeof(int));
//        
//        for (j = 0; j < nVertices; j++)
//            adjMatrix[i][j] = COMP_INF_COST;
//    }
    
    // scan --------------------------------
    Vertex vertices[nVertices];
    int iVertexFrom, iVertexTo, nArrow;
    int weight;
    
    for (i = 0; i < nVertices; i++) {
        vertices[i].key = i;
        scanf("%d %d", &iVertexFrom, &nArrow); 
        
        vertices[iVertexFrom].adjList = (ArrowTo *)malloc((nArrow + 1) * sizeof(ArrowTo));
        
        for (j = 0; j < nArrow; j++) {
            scanf("%d %d", &iVertexTo, &weight); 
            vertices[iVertexFrom].adjList[j].vertex = &vertices[iVertexTo];
            vertices[iVertexFrom].adjList[j].weight = weight;
        }
        
        vertices[iVertexFrom].adjList[nArrow].vertex = NULL;
    }
    
//    // scan result
//    for (i = 0; i < nVertices; i++) {
//        printf("%d:", i);
//        for (j = 0; !isNullArrow(vertices[i].adjList[j]); j++) {
//            printf(" %d %d",
//                    vertices[i].adjList[j].vertex->key,
//                    vertices[i].adjList[j].weight);
//        }
//        printf("\n");
//    }
    
    dijkstra(vertices, nVertices, 0);
    
    for (i = 0; i < nVertices; i++)
        printf("%d %d\n", i, vertices[i].discoveryCost);

    return (EXIT_SUCCESS);
}




Measured memory_bytes: 9616