题目：

题解：

typedef struct{int row;int column;int height;
} Element;struct Pri_Queue;
typedef struct Pri_Queue *P_Pri_Queue;
typedef Element Datatype;struct Pri_Queue{int n;Datatype *pri_qu;
};/*优先队列插入*/
P_Pri_Queue add_pri_queue(P_Pri_Queue pq, Datatype x){int i;if(pq->n == 0){pq->pri_qu[0] = x; pq->n ++; return(pq);}else{for(i = pq->n; (i > 0) && (x.height < pq->pri_qu[(i - 1) / 2].height); i = (i - 1) / 2){pq->pri_qu[i] = pq->pri_qu[(i - 1) / 2];}}pq->pri_qu[i] = x;pq->n ++;return(pq);
}/*优先队列删除*/
P_Pri_Queue del_pri_queue(P_Pri_Queue pq){int i = 0;if(pq->n > 1){while(i <= (pq->n - 2) / 2){if((pq->pri_qu[pq->n - 1].height > pq->pri_qu[2 * i + 1].height) || \((2 * i + 2 <= pq->n - 1) && (pq->pri_qu[pq->n - 1].height > pq->pri_qu[2 * i + 2].height))){if(2 * i + 2 <= pq->n - 1){if(pq->pri_qu[2 * i + 1].height > pq->pri_qu[2 * i + 2].height){pq->pri_qu[i] = pq->pri_qu[2 * i + 2];i = 2 * i + 2;}else{pq->pri_qu[i] = pq->pri_qu[2 * i + 1];i = 2 * i + 1;}}else{pq->pri_qu[i] = pq->pri_qu[2 * i + 1];i = 2 * i + 1;}}else{pq->pri_qu[i] = pq->pri_qu[pq->n - 1];pq->n --;return(pq);}}}pq->pri_qu[i] = pq->pri_qu[pq->n - 1];pq->n --;return(pq);
}int trapRainWater(int** heightMap, int heightMapSize, int* heightMapColSize){if((heightMapSize < 3) || (*heightMapColSize < 3)) return(0);int Used_heightMap[112][112] = {0}, i, j, ans = 0;int direct[4][2] = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};Datatype x;P_Pri_Queue pq;pq = (P_Pri_Queue)malloc(sizeof(struct Pri_Queue));pq->n = 0; pq->pri_qu = (Datatype*)malloc(sizeof(Datatype) * heightMapSize * (*heightMapColSize));for(i = 0; i < heightMapSize + 2; i ++) Used_heightMap[i][0] = 1;for(i = 0; i < heightMapSize + 2; i ++) Used_heightMap[i][1] = 1;for(i = 0; i < heightMapSize + 2; i ++) Used_heightMap[i][*heightMapColSize] = 1;for(i = 0; i < heightMapSize + 2; i ++) Used_heightMap[i][*heightMapColSize + 1] = 1;for(j = 0; j < *heightMapColSize + 2; j ++) Used_heightMap[0][j] = 1;for(j = 0; j < *heightMapColSize + 2; j ++) Used_heightMap[1][j] = 1;for(j = 0; j < *heightMapColSize + 2; j ++) Used_heightMap[heightMapSize][j] = 1;for(j = 0; j < *heightMapColSize + 2; j ++) Used_heightMap[heightMapSize + 1][j] = 1;for(i = 1; i < heightMapSize - 1; i ++){x.row = i; x.column = 0; x.height = heightMap[i][0];add_pri_queue(pq, x);}for(i = 1; i < heightMapSize - 1; i ++){x.row = i; x.column = *heightMapColSize - 1; x.height = heightMap[i][*heightMapColSize - 1];add_pri_queue(pq, x);}for(j = 1; j < *heightMapColSize - 1; j ++){x.row = 0; x.column = j; x.height = heightMap[0][j];add_pri_queue(pq, x);}for(j = 1; j < *heightMapColSize - 1; j ++){x.row = heightMapSize - 1; x.column = j; x.height = heightMap[heightMapSize - 1][j];add_pri_queue(pq, x);}while(pq->n > 0){for(i = 0; i < 4; i ++){if(Used_heightMap[pq->pri_qu[0].row + 1 + direct[i][0]][pq->pri_qu[0].column + 1 + direct[i][1]] == 0){if(heightMap[pq->pri_qu[0].row + direct[i][0]][pq->pri_qu[0].column + direct[i][1]] < pq->pri_qu[0].height){ans += pq->pri_qu[0].height - heightMap[pq->pri_qu[0].row + direct[i][0]][pq->pri_qu[0].column + direct[i][1]];x.height = pq->pri_qu[0].height;}else{x.height = heightMap[pq->pri_qu[0].row + direct[i][0]][pq->pri_qu[0].column + direct[i][1]];}x.row = pq->pri_qu[0].row + direct[i][0]; x.column = pq->pri_qu[0].column + direct[i][1];add_pri_queue(pq, x);Used_heightMap[pq->pri_qu[0].row + 1 + direct[i][0]][pq->pri_qu[0].column + 1 + direct[i][1]] = 1;}}//printf("row = %d, column =  %d, height = %d, n = %d\n", pq->pri_qu[0].row, pq->pri_qu[0].column, pq->pri_qu[0].height, pq->n);del_pri_queue(pq);//printf("row = %d, column =  %d, height = %d, n = %d\n", pq->pri_qu[0].row, pq->pri_qu[0].column, pq->pri_qu[0].height, pq->n);}return(ans);
}