poj2253--dijkstra

昨天学的dijkstra算法，尝试了下，解这种裸算法的题目还是很方便的啊~

#define LOCAL #include #include #include #define MAXN 1000000 + 10 typedef struct Point { double x; double y; } ; Point points[MAXN]; double minJump[MAXN]; int redPoint[MAXN]; int bluePoint[MAXN]; //计算两点间的距离 double calcMinJump(Point point1, Point point2) { double distance; distance = sqrt((point1.x - point2.x) * (point1.x - point2.x) + (point1.y - point2.y) * (point1.y - point2.y)); return distance; } int main() { #ifdef LOCAL freopen("C:\\Users\\Administrator\\Desktop\\ACMTempIn.txt", "r", stdin); freopen("C:\\Users\\Administrator\\Desktop\\ACMTempOut.txt", "w", stdout); #endif int cases; int i, j, min, count = 0; //数据输入 while(scanf("%d", &cases) && cases != 0) { memset(points, 0, sizeof(points)); count ++; for(i = 0; i < cases; i++) { scanf("%lf%lf", &points[i].x, &points[i].y); } //初始化红点集和蓝点集 memset(redPoint, 0, sizeof(redPoint)); memset(bluePoint, 0, sizeof(bluePoint)); memset(minJump, 0, sizeof(minJump)); redPoint[0] = 1; bluePoint[0] = 0; for(i = 1; i < cases; i++) { bluePoint[i] = 1; } for(i = 1; i < cases; i++) { minJump[i] = calcMinJump(points[i],points[0]); } //遍历蓝点集 for(i = 1; i < cases; i++) { //获得最短路径的蓝点 for(min = 1; bluePoint[min] == 0;)min++; for(j = min; j < cases; j++) if((minJump[j] < minJump[min]) && bluePoint[j] == 1) min = j; bluePoint[min] = 0; redPoint[min] = 1; for(j = 0; j < cases; j++) { if(min != j) { double temp = calcMinJump(points[min], points[j]); if(calcMinJump(points[min], points[j]) < minJump[min]) temp = minJump[min]; if(minJump[j] > temp) { minJump[j] = temp; } } } } printf("Scenario #%d\nFrog Distance = %.3lf\n\n", count, minJump[1]); } return 0; }